GEML × Carve Comparison

Aspect	Carve	GEML
Problem it solves	A successor to Djot that removes Markdown's twenty years of ambiguity and is easy for writers to learn and remember (`docs/technical-rationale.md`)	Let people and AI agents co-write one document: plain text for people, addressable, verifiable and versioned for machines (first draft §1, "addressable everything")
Stated ancestry	Djot, Org-mode (`/italic/`), Creole (`\|=`), AsciiDoc (admonitions), CriticMarkup (Init commit README)	Markdown/CommonMark, AsciiDoc, reStructuredText, Org-mode, MyST, Mermaid/Graphviz, TOML (2026-06-17 draft preface and commit message); neither Djot nor Carve is among them. Attribute syntax credited to Pandoc as its ancestor (`COMPARISON.md`, 06-18); the website's "Influences" section (10-01) adds djot
Relation to Markdown	Deliberately changes meanings: `x` is bold, `_x_` is underline; a `.crv` file must not go to a Markdown parser	Backward compatible with Markdown: keeps its inline syntax, and the CLI reads and writes blocks in a `.md` file directly, with no conversion, writing Markdown back
Block model	A dedicated syntax per kind of content: ``` code, $$` math, `:::` containers, `\|=` tables, `^` captions, `---` frontmatter	One typed-block primitive, `=== type {attrs}`, carries code, math, tables, diagrams, data, notes and metadata; a type registry decides how the body is read
External content	The include processor takes only Carve or plain text, expanded by the host outside the parser (`includes.md`)	`src=` reaches source-file line spans, CSV, JSON/JSONL/YAML and blocks in other documents; local sources are checked at build time
Unit of action	The whole document: render, fmt, lint, diff, merge, migrate, flatten	The element an address selects: a block, a section, prose, a line span, a cell; one set of verbs across the command line, MCP and profiles
Unresolvable reference	Kept as written and left for the host to resolve (`extension-contract.md` §12.4)	A build error; the document does not conform (spec §5.2, §8)
Variables / interpolation	Listed under dismissed syntax: it mixes markup with templating (`dismissed-syntax.md`)	`{{key}}` is core syntax, valued from `=== meta`; a misspelled key is an error
Raw HTML	Bare HTML is literal text; ```=html passthrough is on by default in the JS and Rust engines	No HTML channel at all; documents are data, never code (spec §9.1)
Block identity	Author-written `{#id}` plus session-scoped node ids, which have no spelling in the source and end with the session (`ast-node-identity.md`)	An `#id` written in the source, plus prose addresses derived from neighbouring blocks; the same key serves reads, writes, checks and history
Metadata	`---` YAML frontmatter, kept raw	`=== meta` key-value blocks with typed values (string, number, boolean); several merge; `#meta` is addressable
History	No stored history; compares two files (`carve diff`) and merges three ways (`carve merge`)	A `.gemlhistory` sidecar: an append-only revision chain, hash-verified, with single-block revert

Aspect

Carve

GEML

Problem it solves

A successor to Djot that removes Markdown's twenty years of ambiguity and is easy for writers to learn and remember (docs/technical-rationale.md)

Let people and AI agents co-write one document: plain text for people, addressable, verifiable and versioned for machines (first draft §1, "addressable everything")

Stated ancestry

Djot, Org-mode (/italic/), Creole (|=), AsciiDoc (admonitions), CriticMarkup (Init commit README)

Markdown/CommonMark, AsciiDoc, reStructuredText, Org-mode, MyST, Mermaid/Graphviz, TOML (2026-06-17 draft preface and commit message); neither Djot nor Carve is among them. Attribute syntax credited to Pandoc as its ancestor (COMPARISON.md, 06-18); the website's "Influences" section (10-01) adds djot

Relation to Markdown

Deliberately changes meanings: *x* is bold, _x_ is underline; a .crv file must not go to a Markdown parser

Backward compatible with Markdown: keeps its inline syntax, and the CLI reads and writes blocks in a .md file directly, with no conversion, writing Markdown back

Block model

A dedicated syntax per kind of content: ``` code, $$` math, ::: containers, |= tables, ^ captions, --- frontmatter

One typed-block primitive, === type {attrs}, carries code, math, tables, diagrams, data, notes and metadata; a type registry decides how the body is read

External content

The include processor takes only Carve or plain text, expanded by the host outside the parser (includes.md)

src= reaches source-file line spans, CSV, JSON/JSONL/YAML and blocks in other documents; local sources are checked at build time

Unit of action

The whole document: render, fmt, lint, diff, merge, migrate, flatten

The element an address selects: a block, a section, prose, a line span, a cell; one set of verbs across the command line, MCP and profiles

Unresolvable reference

Kept as written and left for the host to resolve (extension-contract.md §12.4)

A build error; the document does not conform (spec §5.2, §8)

Variables / interpolation

Listed under dismissed syntax: it mixes markup with templating (dismissed-syntax.md)

{{key}} is core syntax, valued from === meta; a misspelled key is an error

Raw HTML

Bare HTML is literal text; ```=html passthrough is on by default in the JS and Rust engines

No HTML channel at all; documents are data, never code (spec §9.1)

Block identity

Author-written {#id} plus session-scoped node ids, which have no spelling in the source and end with the session (ast-node-identity.md)

An #id written in the source, plus prose addresses derived from neighbouring blocks; the same key serves reads, writes, checks and history

Metadata

--- YAML frontmatter, kept raw

=== meta key-value blocks with typed values (string, number, boolean); several merge; #meta is addressable

History

No stored history; compares two files (carve diff) and merges three ways (carve merge)

A .gemlhistory sidecar: an append-only revision chain, hash-verified, with single-block revert

Construct	Carve	GEML	Verdict	Notes / common source
Inline
Italic	`/x/`	`x`	Different design	Carve takes it from Org-mode; GEML keeps Markdown
Bold	`x`	`x`	Same form, different meaning	`x` is bold in Carve and italic in GEML (probe P7)
Bold italic	`/x/`	no dedicated form	Carve only	Carve's own
Underline	`_x_`	none; `_x_` stays literal	Carve only	Probe P7
Strikethrough	`~x~`	`~~x~~`	Different design	GEML uses the GFM spelling; a single tilde is not syntax in GEML
Highlight	`=x=`	none	Carve only	`==x==` in Init; single character since 06-11
Superscript / subscript	`{^x^}` `{,x,}`	none	Carve only	Braced forced form from Djot
Intraword forced delimiters	`H{,2,}O` etc.	none	Carve only	Djot style
Code span	`x`	`x`	Shared heritage	Markdown (2004)
Inline literal	!`x`	none	Carve only	Added to Carve 07-21
Inline math	$`x`	$x$	Different design	Carve moved to Djot's form on 05-21; GEML uses the LaTeX/Pandoc $…$
Raw inline output	`x`{=html}	none; the spec forbids it	Carve only	From Djot / Pandoc RawInline
Link	`[t](url)`	`[t](url)`	Shared heritage	Markdown (2004)
Reference link	`[t][ref]` + `[ref]: url`	none	Carve only	Markdown has it; GEML left it out
In-document anchor link	`[t](#id)`	`[t](#id)`	Shared heritage	Markdown spelling in both; only GEML checks that the target exists (probe P1)
Cross-reference with automatic text	`</#id>`	`[[#id]]`	Different design	The concept is LaTeX `\ref` and AsciiDoc `<<id>>`; GEML's first draft cites AsciiDoc for it
Cross-document reference	a plain link `[t](a.crv#id)`, unchecked	`[t](a.geml#id)` `[[a.geml#id]]`, checked	Different design	Probe P3: Carve accepts a missing target; GEML reports it
Wiki-style link	`[Heading text][]`; optional extension `[[Heading]]`	`[[#id]]`, naming an id rather than heading text	Different design	`[[ ]]` comes from MediaWiki / Obsidian / Logseq
Image / media	`![alt](src)` image	`![alt](src)` image, audio or video, inferred from the extension	Shared heritage	Markdown; GEML widened it to in-place media (06-17)
Inline content projection	`{{ path #id }}` include processor, outside the core	`![[#id]]` core syntax, projecting a text block	Different design	`![[ ]]` is Obsidian's embed spelling
Footnote reference	`[^l]`, defined by `[^l]: …`; inline `^[…]`	`[^id]`, pointing at any block with that id	Shared heritage	PHP Markdown Extra (2005); the definitions differ
Metadata interpolation	dismissed	`{{key}}`, escaped as `\{{`	GEML only	Carve rejects it in `dismissed-syntax.md`; GEML added it 06-18, and an undefined key is an error (probe P5)
The `{{ … }}` pair	file include `{{ path #id @lines:N-M }}`	metadata interpolation `{{key}}`	Same form, different meaning	Carve requires inner spaces, so `{{path}}` is plain text; GEML's `{{key}}` has the same shape as Mustache or Hugo templates
Inline span and attributes	`[t]{.c}`, `/x/{.c}`	only links and media take attributes	Carve only	Djot's span
Semantic spans	`[Tab]{kbd}` `{abbr=…}` `{time=…}`	none	Carve only	Carve's own
Language tag	`{:fr}` `{:}`	none	Carve only	BCP 47
Inline extension	`:name[x]{a}`	none	Carve only	Resembles remark-directive
Symbol	`:rocket:`	none	Carve only	Djot symbol
Mention / tag	`@user` `#tag`	none	Carve only	Social-platform convention
Editorial marks	`{+ +}` `{- -}` `{~a~>b~}` `{#note#}`	none	Carve only	CriticMarkup
Smart typography	`--` `...` `-->` `(c)`	no substitution	Carve only	Djot / SmartyPants
Escape	`\` + ASCII punctuation	`\` + ASCII punctuation	Shared heritage	CommonMark (2014)
Hard line break	`\` at line end	`\` at line end	Shared heritage	CommonMark
No-break space	`\␠` mid-line	none	Carve only	Djot
Blocks
Heading	`#`…`######`	`#`…`######`	Shared heritage	Markdown ATX headings; neither has setext
Explicit heading id	on the line above: `{#id}`⏎`# Title`	at the line end: `# Title {#id}`	Different design	Carve dropped the trailing form on 06-04; GEML settled on the line end on 06-17 (Pandoc / kramdown style)
Automatic heading id	keeps case: `id="Intro"`	normative derivation: lower-case, NFD, strip diacritics, whitespace to `-`	Different design	Probe P1 renders `<section id="Intro">`; GEML spec §4 gives a six-step derivation
Prose addresses	none	`#prev-between-next`, `#container-before-next`	GEML only	Prose between two blocks gets a unique address from both ends; inserting a block makes the old address stop resolving
Paragraph / bullet list	`-` `*`	`-` `*`	Shared heritage	Markdown
Ordered list	`1.` `1)` `a.` `i.` and auto-numbered `.`	`1.`	Different design	Carve's is richer
Task list	`[ ]` `[x]` plus `[-] [>] [?] [_]`	`[ ]` `[x]`	Shared heritage	GitHub (2013); Carve's extra states come from Org TODO
Block quote	`>`, `::: >`, `^` attribution	none	Carve only	GEML's syntax inventory has no block quote
Thematic break	`---` `***` `___`	left out on purpose	Carve only	GEML's 06-17 fence rationale: `-` clashes with breaks, frontmatter, setext and lists, so the fence uses `=`
Code block	```lang "Header" [Label]	`=== code {lang=… src=…}`	Different design	In GEML a backtick run is only a shield and never opens a code block
Raw block	```=html, passed through by default	none	Carve only	Probe P8: `<script>` comes out unchanged
Container / admonition	`::: note "Title"` … `:::`	`=== note` … `===`	Different design	`:::` is the Pandoc / MyST / Djot fence; GEML's first draft used it for seven minutes and switched to `===` at 07:17
Fence closing and nesting	exact colon count; inner fences add a colon	exact equals count; outer fences are longer	Different design	Equal-length closing is the common fence rule (CommonMark code fences)
Unknown type	`::: word` → `<div class="word">`	`=== word` → warning, body kept	Different design	GEML's first draft (§3) already made it a forward-compatible warning
One typed-block primitive	none	`=== type {attrs}` + a type registry (raw / flow / key-value)	GEML only	Code, math, tables, views, data, diagrams, embeds, notes, text and metadata share one fence
Line block (verse)	`::: \|`	none	Carve only	reST / Djot
Definition list	`:: term` / `: definition`	none	Carve only
Continuation marker	a lone `+` line	none	Carve only	Carve's own
Display math	$$`…`	`=== math`	Different design
Comment line	`%%`, plus `%%%` blocks, trailing `%%`, `{% %}`	line-start `%%` only	Shared heritage	Obsidian `%%…%%` and Mermaid `%%` comment lines (GEML hosts Mermaid). GEML added it 06-18 to replace the forbidden `<!-- -->`
Hidden but checked block	none	`{hidden}`	GEML only	A source table that only feeds a chart: in the model, reference-checked, not rendered
Metadata	`---` YAML frontmatter (`---toml` `---json`)	`=== meta` key-value, typed, mergeable, addressable as `#meta`	Different design	GEML explicitly has no `---` frontmatter
Caption	`^ text` on the next line, auto-numbered `Figure #`	`caption="…"` attribute	Different design	Carve's is stronger: numbering, listings, equation captions
Composite figure	`::: figure`, panels "Figure 2a"	none	Carve only
Attribute object contents	`{#id .class key=val}`	`{#id .class key=val}`	Shared heritage	Long established in PHP Markdown Extra, kramdown, Pandoc and MyST; in GEML's 06-17 draft EBNF
Where attributes attach	the line above a block, floating past invisible blocks	in the fence line `=== t {…}`, at a heading's line end	Different design	GEML lets a long attribute object continue over lines with `\`
Bare attribute word	`word` → `word=""`	`word` → boolean `true`; values are string, number or boolean	Different design	An open question in GEML's first draft: borrow TOML's typing discipline
Abbreviation definition	`*[HTML]: …`	none	Carve only	PHP Markdown Extra
Include / embed	`{{ path #id @lines:N-M @shift:N }}`	`=== embed {src=doc.geml#id}`; code `src=f#L10-20`	Different design	Carve has more parameters; in GEML an out-of-range line span is an error (probe P4)
Placement directives	`::: toc` `::: footnotes` etc.	none	Carve only
Tabs / citations	`::: tab`, `[@key]` (optional)	none	Carve only
Tables
Table shape	a bare pipe table, `\|=` marks header cells	a GFM pipe table inside `=== table`	Different design	`\|=` comes from Creole; pipe tables from PHP Markdown Extra / GFM
Alignment	glued `< ~ >`, vertical `^ ~ v`, inherit `?`	GFM delimiter row `:--:`	Different design	Carve's is stronger
Merged cells	`^` up, `<` left	none	Carve only
Continuation rows / header rows	`+` rows, `{header-rows=N}`	none	Carve only
Data-form body	none	`format=csv\|tsv` `header=` `delim=`	GEML only	"Two table forms" in the 06-17 draft
External data source	none	`src=data.csv` or http(s)	GEML only
Derived view	none	`=== view {src=#t compute=… summary=…}`	GEML only	Computed columns, a summary row, printf display formats (probe P6)
Data block	none	`=== data {format=json\|jsonl schema=…}`	GEML only	A record array can feed a chart directly
Graphics
Hosting an external diagram DSL	```mermaid etc., optional feature (06-21)	`=== diagram {format=mermaid}` (06-17 draft)	Different design	GitLab, GitHub and Obsidian had mermaid code blocks first; GEML's draft rule is "host a DSL, never invent one"
Charts	```chart Chart.js JSON, numbers written into the body	`format=geml-chart data=#table x= y=`, checked by column	Different design	Only GEML's charts bind to data in the document (probe P6)
Code graph	none	`format=geml-code-graph`	GEML only	GEP-0002 / 0003 (07-01)
Addressing
Labeled closing fence	none; colons are counted	`=== #id`	GEML only	Added 06-29: the closing line names the block it closes, so nothing has to be counted
Inner-unit coordinates	none	`#fy[2]` `#fy[2]["Q1"]` `#fy["Q1"]` `#fy[summary]`	GEML only	GEP-0011 (09-03): reference one row, cell or column of a table, across documents too, and have it checked
Address for content without an id	AST path (JSON Pointer), session-scoped node id	content address `@<hex>` (first 8 hex of SHA-256), derived prose addresses	Different design	GEML's `@<hex>` arrived 08-04 and finds a block by its content; Carve's paths move when the structure changes
Selecting blocks by type / attribute	`carve_select_ast_nodes` (MCP, 09-09)	`'=== code {lang=py}'` `{.warn}` `--within` (09-30)	Different design	GEML's commit message cites mq's query language
Characters and files
Input normalization	strip one BOM, unify line endings, U+0000→U+FFFD	the same (§0, 07-25)	Shared heritage	CommonMark §2, "Insecure characters"; GEML added it after a bug where a BOM turned `# Title` into a paragraph
Extension / media type	`.crv`, clipboard `text/x-carve`	`.geml`, `text/vnd.geml` (IANA registration pending)	Different design

Construct

Carve

GEML

Verdict

Notes / common source

Inline

Italic

/x/

*x*

Different design

Carve takes it from Org-mode; GEML keeps Markdown

Bold

*x*

**x**

Same form, different meaning

*x* is bold in Carve and italic in GEML (probe P7)

Bold italic

/*x*/

no dedicated form

Carve only

Carve's own

Underline

_x_

none; _x_ stays literal

Carve only

Probe P7

Strikethrough

~x~

~~x~~

Different design

GEML uses the GFM spelling; a single tilde is not syntax in GEML

Highlight

=x=

none

Carve only

==x== in Init; single character since 06-11

Superscript / subscript

{^x^} {,x,}

none

Carve only

Braced forced form from Djot

Intraword forced delimiters

H{,2,}O etc.

none

Carve only

Djot style

Code span

`x`

Shared heritage

Markdown (2004)

Inline literal

!`x`

none

Carve only

Added to Carve 07-21

Inline math

$`x`

$x$

Different design

Carve moved to Djot's form on 05-21; GEML uses the LaTeX/Pandoc $…$

Raw inline output

`x`{=html}

none; the spec forbids it

Carve only

From Djot / Pandoc RawInline

Link

[t](url)

Shared heritage

Markdown (2004)

Reference link

[t][ref] + [ref]: url

none

Carve only

Markdown has it; GEML left it out

In-document anchor link

[t](#id)

Shared heritage

Markdown spelling in both; only GEML checks that the target exists (probe P1)

Cross-reference with automatic text

</#id>

[[#id]]

Different design

The concept is LaTeX \ref and AsciiDoc <<id>>; GEML's first draft cites AsciiDoc for it

Cross-document reference

a plain link [t](a.crv#id), unchecked

[t](a.geml#id) [[a.geml#id]], checked

Different design

Probe P3: Carve accepts a missing target; GEML reports it

Wiki-style link

[Heading text][]; optional extension [[Heading]]

[[#id]], naming an id rather than heading text

Different design

[[ ]] comes from MediaWiki / Obsidian / Logseq

Image / media

![alt](src) image

![alt](src) image, audio or video, inferred from the extension

Shared heritage

Markdown; GEML widened it to in-place media (06-17)

Inline content projection

{{ path #id }} include processor, outside the core

![[#id]] core syntax, projecting a text block

Different design

![[ ]] is Obsidian's embed spelling

Footnote reference

[^l], defined by [^l]: …; inline ^[…]

[^id], pointing at any block with that id

Shared heritage

PHP Markdown Extra (2005); the definitions differ

Metadata interpolation

dismissed

{{key}}, escaped as \{{

GEML only

Carve rejects it in dismissed-syntax.md; GEML added it 06-18, and an undefined key is an error (probe P5)

The {{ … }} pair

file include {{ path #id @lines:N-M }}

metadata interpolation {{key}}

Same form, different meaning

Carve requires inner spaces, so {{path}} is plain text; GEML's {{key}} has the same shape as Mustache or Hugo templates

Inline span and attributes

[t]{.c}, /x/{.c}

only links and media take attributes

Carve only

Djot's span

Semantic spans

[Tab]{kbd} {abbr=…} {time=…}

none

Carve only

Carve's own

Language tag

{:fr} {:}

none

Carve only

BCP 47

Inline extension

:name[x]{a}

none

Carve only

Resembles remark-directive

Symbol

:rocket:

none

Carve only

Djot symbol

Mention / tag

@user #tag

none

Carve only

Social-platform convention

Editorial marks

{+ +} {- -} {~a~>b~} {#note#}

none

Carve only

CriticMarkup

Smart typography

-- ... --> (c)

no substitution

Carve only

Djot / SmartyPants

Escape

\ + ASCII punctuation

Shared heritage

CommonMark (2014)

Hard line break

\ at line end

Shared heritage

CommonMark

No-break space

\␠ mid-line

none

Carve only

Djot

Blocks

Heading

#…######

Shared heritage

Markdown ATX headings; neither has setext

Explicit heading id

on the line above: {#id}⏎# Title

at the line end: # Title {#id}

Different design

Carve dropped the trailing form on 06-04; GEML settled on the line end on 06-17 (Pandoc / kramdown style)

Automatic heading id

keeps case: id="Intro"

normative derivation: lower-case, NFD, strip diacritics, whitespace to -

Different design

Probe P1 renders <section id="Intro">; GEML spec §4 gives a six-step derivation

Prose addresses

none

#prev-between-next, #container-before-next

GEML only

Prose between two blocks gets a unique address from both ends; inserting a block makes the old address stop resolving

Paragraph / bullet list

- *

Shared heritage

Markdown

Ordered list

1. 1) a. i. and auto-numbered .

1.

Different design

Carve's is richer

Task list

[ ] [x] plus [-] [>] [?] [_]

[ ] [x]

Shared heritage

GitHub (2013); Carve's extra states come from Org TODO

Block quote

>, ::: >, ^ attribution

none

Carve only

GEML's syntax inventory has no block quote

Thematic break

--- *** ___

left out on purpose

Carve only

GEML's 06-17 fence rationale: - clashes with breaks, frontmatter, setext and lists, so the fence uses =

Code block

```lang "Header" [Label]

=== code {lang=… src=…}

Different design

In GEML a backtick run is only a shield and never opens a code block

Raw block

```=html, passed through by default

none

Carve only

Probe P8: <script> comes out unchanged

Container / admonition

::: note "Title" … :::

=== note … ===

Different design

::: is the Pandoc / MyST / Djot fence; GEML's first draft used it for seven minutes and switched to === at 07:17

Fence closing and nesting

exact colon count; inner fences add a colon

exact equals count; outer fences are longer

Different design

Equal-length closing is the common fence rule (CommonMark code fences)

Unknown type

::: word → <div class="word">

=== word → warning, body kept

Different design

GEML's first draft (§3) already made it a forward-compatible warning

One typed-block primitive

none

=== type {attrs} + a type registry (raw / flow / key-value)

GEML only

Code, math, tables, views, data, diagrams, embeds, notes, text and metadata share one fence

Line block (verse)

::: |

none

Carve only

reST / Djot

Definition list

:: term / : definition

none

Carve only

Continuation marker

a lone + line

none

Carve only

Carve's own

Display math

$$`…`

=== math

Different design

Comment line

%%, plus %%% blocks, trailing %%, {% %}

line-start %% only

Shared heritage

Obsidian %%…%% and Mermaid %% comment lines (GEML hosts Mermaid). GEML added it 06-18 to replace the forbidden 

Hidden but checked block

none

{hidden}

GEML only

A source table that only feeds a chart: in the model, reference-checked, not rendered

Metadata

--- YAML frontmatter (---toml ---json)

=== meta key-value, typed, mergeable, addressable as #meta

Different design

GEML explicitly has no --- frontmatter

Caption

^ text on the next line, auto-numbered Figure #

caption="…" attribute

Different design

Carve's is stronger: numbering, listings, equation captions

Composite figure

::: figure, panels "Figure 2a"

none

Carve only

Attribute object contents

{#id .class key=val}

Shared heritage

Long established in PHP Markdown Extra, kramdown, Pandoc and MyST; in GEML's 06-17 draft EBNF

Where attributes attach

the line above a block, floating past invisible blocks

in the fence line === t {…}, at a heading's line end

Different design

GEML lets a long attribute object continue over lines with \

Bare attribute word

word → word=""

word → boolean true; values are string, number or boolean

Different design

An open question in GEML's first draft: borrow TOML's typing discipline

Abbreviation definition

*[HTML]: …

none

Carve only

PHP Markdown Extra

Include / embed

{{ path #id @lines:N-M @shift:N }}

=== embed {src=doc.geml#id}; code src=f#L10-20

Different design

Carve has more parameters; in GEML an out-of-range line span is an error (probe P4)

Placement directives

::: toc ::: footnotes etc.

none

Carve only

Tabs / citations

::: tab, [@key] (optional)

none

Carve only

Tables

Table shape

a bare pipe table, |= marks header cells

a GFM pipe table inside === table

Different design

|= comes from Creole; pipe tables from PHP Markdown Extra / GFM

Alignment

glued < ~ >, vertical ^ ~ v, inherit ?

GFM delimiter row :--:

Different design

Carve's is stronger

Merged cells

^ up, < left

none

Carve only

Continuation rows / header rows

+ rows, {header-rows=N}

none

Carve only

Data-form body

none

format=csv|tsv header= delim=

GEML only

"Two table forms" in the 06-17 draft

External data source

none

src=data.csv or http(s)

GEML only

Derived view

none

=== view {src=#t compute=… summary=…}

GEML only

Computed columns, a summary row, printf display formats (probe P6)

Data block

none

=== data {format=json|jsonl schema=…}

GEML only

A record array can feed a chart directly

Graphics

Hosting an external diagram DSL

```mermaid etc., optional feature (06-21)

=== diagram {format=mermaid} (06-17 draft)

Different design

GitLab, GitHub and Obsidian had mermaid code blocks first; GEML's draft rule is "host a DSL, never invent one"

Charts

```chart Chart.js JSON, numbers written into the body

format=geml-chart data=#table x= y=, checked by column

Different design

Only GEML's charts bind to data in the document (probe P6)

Code graph

none

format=geml-code-graph

GEML only

GEP-0002 / 0003 (07-01)

Addressing

Labeled closing fence

none; colons are counted

=== #id

GEML only

Added 06-29: the closing line names the block it closes, so nothing has to be counted

Inner-unit coordinates

none

#fy[2] #fy[2]["Q1"] #fy["Q1"] #fy[summary]

GEML only

GEP-0011 (09-03): reference one row, cell or column of a table, across documents too, and have it checked

Address for content without an id

AST path (JSON Pointer), session-scoped node id

content address @<hex> (first 8 hex of SHA-256), derived prose addresses

Different design

GEML's @<hex> arrived 08-04 and finds a block by its content; Carve's paths move when the structure changes

Selecting blocks by type / attribute

carve_select_ast_nodes (MCP, 09-09)

'=== code {lang=py}' {.warn} --within (09-30)

Different design

GEML's commit message cites mq's query language

Characters and files

Input normalization

strip one BOM, unify line endings, U+0000→U+FFFD

the same (§0, 07-25)

Shared heritage

CommonMark §2, "Insecure characters"; GEML added it after a bug where a BOM turned # Title into a paragraph

Extension / media type

.crv, clipboard text/x-carve

.geml, text/vnd.geml (IANA registration pending)

Different design

P1 · A link to a block that does not exist

Both link forms point at a missing #budget.

Carve

See [the budget](#budget) and </#budget>.

$ carve lint p1.crv
p1.crv:3:31 broken-crossref — Cross-reference </#budget>
has no matching heading id; it renders as the literal
text "</#budget>".

Reports the cross-reference only; the plain link […](#budget) passes, and render exits 0

GEML

See [the budget](#budget) and [[#budget]].

$ geml check p1.geml
error: unresolved reference `#budget` (line 3)
error: unresolved reference `#budget` (line 3)
2 error(s)

Both reported, exit 1

P2 · Duplicate id

Two headings share an id. Both languages catch this one.

Carve

p2.crv:5:1 duplicate-heading-id — Duplicate heading id "a"

Reported by lint; render still emits two id="a"

GEML

error: duplicate id `#a` (first defined at line 1) (line 3)

Error, exit 1

P3 · A cross-document reference to a missing target

The other document exists, but has no #nope.

Carve

See [x](other.crv#nope).

$ carve lint p3.crv      → no output, exit 0
$ carve p3.crv
<p>See <a href="other.crv#nope">x</a>.</p>

Not detected

GEML

See [x](other.geml#nope).

error: unresolved reference `other.geml#nope` (line 3)
1 error(s)

Error

P4 · A line range of a code file that has since shrunk

code.txt has 10 lines; the document cites lines 50–60.

Carve

{{ code.txt @lines:50-60 }}

$ carve lint p4.crv      → no output, exit 0
$ carve p4.crv           → warning on stderr, exit 0
p4.crv:3:1 include-lines-out-of-range - Include line
range for "code.txt" starts past end of file.
<p>{{ code.txt <span class="mention"><strong>@lines
</strong></span>:50-60 }}</p>

A warning only; the output falls back to literal text, with @lines read as a mention

GEML

=== code {src=code.txt#L50-60}
===

error: code source `code.txt#L50-60`: the file has
10 line(s), so lines 50-60 no longer exist — the range
is stale (line 3)

Error, naming the stale range

P5 · Metadata interpolation with one misspelled key

product is right; prodct is a typo.

Carve

---
product: Acme
---
Welcome to {{product}}, also {{prodct}}.

<p>Welcome to {{product}}, also {{prodct}}.</p>

Not a feature (dismissed by design); both stay literal

GEML

=== meta
product = "Acme"
===
Welcome to {{product}}, also {{prodct}}.

error: unknown metadata reference `{{prodct}}` (line 5)

The misspelled key is caught

P6 · Charts and table data

The table has Q1 and Q2. One chart plots the first-half total; another names a Q3 column that does not exist.

Carve

|= Region |= Q1 |= Q2 |
| North | 10 | 12 |
| South |  7 |  9 |
^ Sales by region

``` chart
{"type":"bar","data":{"labels":["North","South"],
 "datasets":[{"label":"Q3","data":[99,99]}]}}
```

$ carve lint p6.crv      → no output, exit 0

The chart's numbers are typed into its JSON, unconnected to the table; a wrong column or number goes unnoticed

GEML

=== table {#sales}
| Region | Q1 | Q2 |
…
===
=== view {#sales-h1 src=#sales compute="H1 = Q1 + Q2"
  summary="Region = 'Total'; …; H1 = sum(H1)"}
===
=== diagram {format=geml-chart data=#sales-h1 x=Region y=H1}
===
=== diagram {format=geml-chart data=#sales x=Region y=Q3}
===

error: chart: column `Q3` not found in table (line 16)

#sales-h1, as computed:
Region | Q1 | Q2 | H1
North  | 10 | 12 | 22
South  |  7 |  9 | 16
Total  | 17 | 21 | 38

The chart binds to the table and its columns are checked; the view derives the computed column and the summary row

P7 · The same line of Markdown

One ordinary line of Markdown, given to both. This is Carve's most distinctive part.

Carve

Plain *emphasis*, **strong** and _under_ with ~~strike~~.

<p>Plain <strong>emphasis</strong>, **strong** and
<u>under</u> with ~~strike~~.</p>

*x* becomes bold, _x_ underline; ** and ~~ are not parsed

GEML

Plain *emphasis*, **strong** and _under_ with ~~strike~~.

<p>Plain <em>emphasis</em>, <strong>strong</strong> and
_under_ with <del>strike</del>.</p>

Same as Markdown

P8 · Raw HTML

Both escape inline HTML as text; they differ on a dedicated passthrough channel.

Carve

```=html
<script>alert(1)</script>
```

<script>alert(1)</script>

Passed through by default (untrusted input needs --safe)

GEML

(the language has no HTML passthrough construct)

Spec §9.1: documents are data, never code

P9 · Change one cell, record a revision, then revert just that block

GEML's core workflow. The Carve side lists its three nearest tools.

Carve

$ carve diff before.crv after.crv
changed  text at line 5 (value: "10" -> "15")
1 structural change

Compares two existing files (08-01) and merges three ways (08-11)

The CLI has no command to read or write one block by id.
carve-mcp's carve_get_block / carve_replace_source
(block read and byte-range replace) were committed 2026-10-05.
No stored document history of any kind.

No revision chain, no single-block revert

GEML

$ geml get doc.geml '#sales'          → that block only
$ geml history save doc.geml
saved 20261006T020617Z-d1701a38
$ … | geml set doc.geml '#sales' --body --in - -o doc.geml
wrote doc.geml — 1 B changed, 399 B of 400 B untouched
$ geml history save doc.geml
$ geml doc.geml --to json              → the view recomputes
North | 15 | 12 | 27
$ geml revert doc.geml '#sales'
reverted #sales to 20261006T020617Z-d1701a38
$ diff before.geml doc.geml            → byte-identical

Addressed reads and writes since 07-01; the history sidecar since 06-17

Capability	Carve	GEML	Verdict
Build-time reference checking	lint checks `</#id>` and duplicate ids; unresolved references are left to the host by design; no cross-document checks	Required by the spec: links, auto-references, cross-document references, footnotes, chart `data=`, code `src` line ranges, `{{key}}` and `schema=` are all checked (06-17 draft §8)	GEML stronger
Read one block by id	include fragment `#id` (heading sections normative 09-14, any block 10-05); `carve_get_block` (10-05)	`geml get #id` (07-01); a heading means its section; line selectors `L27-58`; prose addresses; reads `.md` directly	GEML earlier, broader
Write one block by id	byte-offset source patches (09-07); `carve_replace_source` (10-05)	`set / add / delete / rename / revert` (from 07-01); a write whose result would not parse is refused; `rename` updates every reference; content address `@<hex>` (08-04); `#id` plus `@<hex>` as a write guard (09-30)	GEML earlier, broader
Document history	No stored history; `carve diff` (08-01), three-way `carve merge` (08-11), reversible AST patches	`.gemlhistory` (06-17): append-only revision chain, SHA-256 checks, `verify` rehashes the chain, single-block revert; no three-way merge	Each has strengths
Data layer in the document	none	Data-form tables, external CSV, `view` computed columns and summaries, `data` JSON/JSONL, charts bound by column	GEML only
The word "profile"	Content-restriction presets: full / article / comment / minimal, for untrusted input (06-16)	Application-layer vocabularies: form, media, style, translator, codemap, history, each with its own spec and conformance tests	Same name, different thing
Translation projection	none (UI labels only)	The Chinese spec is a `geml-translator/v1` projection: 17 embeds point at English blocks and follow their changes	GEML only
Code dependency graph	none	codemap: a call graph written as GEML documents whose edges are checked references (run on Flink: 95,958 nodes)	GEML only
Agent skill	`carve-skill` (07-15)	In-repo skill (06-18); `geml skill install`	GEML earlier
MCP server	`carve-mcp` (09-05): parse, lint, migrate, AST patches; block read/replace on 10-05	`geml mcp` (07-25): 11 read/write tools, every write validated first; 4 more tools for a code graph	GEML earlier
Implementations	TypeScript, PHP (forked from djot-php) and Rust, byte-identical (05-13); WASM (06-01); Go / Python / Ruby bindings	TypeScript (06-17); a second implementation in Rust + WASM (10-03)	Carve stronger
Conformance suite	2,223 `.crv`/`.html` pairs (first batch 05-13)	Language-neutral suite (06-28); the 06-17 draft already says "after CommonMark / toml-test"	Common practice
Editors	VS Code, tree-sitter, LSP, Zed (06-01); IntelliJ, Vim, Emacs, Helix, Sublime, Obsidian (08-21) and more	VS Code, Obsidian (06-30); a Chrome viewer; a Logseq bridge	Carve broader
Format bridges	Imports Markdown, HTML, Djot, BBCode; outputs HTML, Markdown, plain text, ANSI, AST; loss reports; pandoc-carve	Markdown → GEML; outputs HTML, Markdown, JSON, canonical GEML	Carve broader
Framework integrations	WordPress, Laravel, Symfony, Hugo, Jekyll, Astro, MkDocs, Docusaurus and others across 60+ repositories	The website playground	Carve broader
Security model	URL denylist, nesting cap, amplification budget, include sandbox; `=html` on by default	§9: no HTML channel, resource limits, one-level confined cross-document resolution, URL scheme allowlist	Different stance
Formatter / lint	`carve fmt` (06-26), about 45 lint rules	`--to geml` canonical output (06-29), Appendix A stable diagnostic codes	Common practice

Capability

Carve

GEML

Verdict

Build-time reference checking

lint checks </#id> and duplicate ids; unresolved references are left to the host by design; no cross-document checks

Required by the spec: links, auto-references, cross-document references, footnotes, chart data=, code src line ranges, {{key}} and schema= are all checked (06-17 draft §8)

GEML stronger

Read one block by id

include fragment #id (heading sections normative 09-14, any block 10-05); carve_get_block (10-05)

geml get #id (07-01); a heading means its section; line selectors L27-58; prose addresses; reads .md directly

GEML earlier, broader

Write one block by id

byte-offset source patches (09-07); carve_replace_source (10-05)

set / add / delete / rename / revert (from 07-01); a write whose result would not parse is refused; rename updates every reference; content address @<hex> (08-04); #id plus @<hex> as a write guard (09-30)

GEML earlier, broader

Document history

No stored history; carve diff (08-01), three-way carve merge (08-11), reversible AST patches

.gemlhistory (06-17): append-only revision chain, SHA-256 checks, verify rehashes the chain, single-block revert; no three-way merge

Each has strengths

Data layer in the document

none

Data-form tables, external CSV, view computed columns and summaries, data JSON/JSONL, charts bound by column

GEML only

The word "profile"

Content-restriction presets: full / article / comment / minimal, for untrusted input (06-16)

Application-layer vocabularies: form, media, style, translator, codemap, history, each with its own spec and conformance tests

Same name, different thing

Translation projection

none (UI labels only)

The Chinese spec is a geml-translator/v1 projection: 17 embeds point at English blocks and follow their changes

GEML only

Code dependency graph

none

codemap: a call graph written as GEML documents whose edges are checked references (run on Flink: 95,958 nodes)

GEML only

Agent skill

carve-skill (07-15)

In-repo skill (06-18); geml skill install

GEML earlier

MCP server

carve-mcp (09-05): parse, lint, migrate, AST patches; block read/replace on 10-05

geml mcp (07-25): 11 read/write tools, every write validated first; 4 more tools for a code graph

GEML earlier

Implementations

TypeScript, PHP (forked from djot-php) and Rust, byte-identical (05-13); WASM (06-01); Go / Python / Ruby bindings

TypeScript (06-17); a second implementation in Rust + WASM (10-03)

Carve stronger

Conformance suite

2,223 .crv/.html pairs (first batch 05-13)

Language-neutral suite (06-28); the 06-17 draft already says "after CommonMark / toml-test"

Common practice

Editors

VS Code, tree-sitter, LSP, Zed (06-01); IntelliJ, Vim, Emacs, Helix, Sublime, Obsidian (08-21) and more

VS Code, Obsidian (06-30); a Chrome viewer; a Logseq bridge

Carve broader

Format bridges

Imports Markdown, HTML, Djot, BBCode; outputs HTML, Markdown, plain text, ANSI, AST; loss reports; pandoc-carve

Markdown → GEML; outputs HTML, Markdown, JSON, canonical GEML

Carve broader

Framework integrations

WordPress, Laravel, Symfony, Hugo, Jekyll, Astro, MkDocs, Docusaurus and others across 60+ repositories

The website playground

Carve broader

Security model

URL denylist, nesting cap, amplification budget, include sandbox; =html on by default

§9: no HTML channel, resource limits, one-level confined cross-document resolution, URL scheme allowlist

Different stance

Formatter / lint

carve fmt (06-26), about 45 lint rules

--to geml canonical output (06-29), Appendix A stable diagnostic codes

Common practice

Profile	What it does	First commit	Commits	Spec and code lines today
`geml-history/v1`	Block-level version sidecar: revisions, keyframes, blobs	06-17	40	2,680
`geml-codemap/v1`	A code call graph written as checkable GEML documents	07-01	147	9,705
`geml-style/v1`	Stylesheets that select into documents and never modify them	08-30	24	7,382
`geml-form/v1`	Form fields addressable inside their block	08-30	14	1,592
`geml-translator/v1`	A translation as a projection of its source, following its changes	09-01	17	2,035
`geml-media/v1`	Audio and video assets, edits and generation lineage	09-15	36	6,685
The profile mechanism itself	§8.6, registration and governance	08-30	27	1,062

Profile

What it does

First commit

Commits

Spec and code lines today

geml-history/v1

Block-level version sidecar: revisions, keyframes, blobs

06-17

2,680

geml-codemap/v1

A code call graph written as checkable GEML documents

07-01

147

9,705

geml-style/v1

Stylesheets that select into documents and never modify them

08-30

7,382

geml-form/v1

Form fields addressable inside their block

08-30

1,592

geml-translator/v1

A translation as a projection of its source, following its changes

09-01

2,035

geml-media/v1

Audio and video assets, edits and generation lineage

09-15

6,685

The profile mechanism itself

§8.6, registration and governance

08-30

1,062

GEML and Carve: one built for typesetting, one for agents

CarveBuilt for typesetting and presentation

GEMLBuilt for agents that manipulate elements

GEML works more like a container

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Carve

GEML

Profiles: from hard-wired into the core to application-layer vocabularies

View: from table attributes to a block of its own

Output: from a dedicated block to general embedding

GEMLOriginal or stronger

CarveOriginal or stronger

Where to check

Scope notes

When each project learned of the other