This document preserves information about Markdown flavors that were included in the original comparison but are no longer actively maintained or widely used.
Status: Student project (circa 2021)
Original Source: vimtaai's markdown-flavors comparison
ExtraMark was a proposed Markdown syntax extension created as a student project. It combined features from multiple existing flavors with planned future enhancements.
| Feature | Syntax | Notes |
|---|---|---|
| Superscript | ^...^ |
|
| Subscript | ~...~ |
|
| Deletion/Strikethrough | {--...--} |
CriticMarkup syntax |
| Insertion | {++...++} |
CriticMarkup syntax |
| Highlight | {==...==} |
CriticMarkup syntax |
| Footnote | [^...] |
Planned feature |
| Task List | - [ ] ... |
Planned feature |
| Table | ✅ | |
| Abbreviation | *[...]: ... |
Planned feature |
| Definition List | : |
ExtraMark represented an interesting attempt to create a unified Markdown syntax that incorporated:
- CriticMarkup conventions for editorial markup (insertions, deletions, highlights)
- Common extensions from MultiMarkdown and Pandoc
- Modern features like task lists that were gaining popularity
While ExtraMark itself didn't see wide adoption, many of its proposed features have since been implemented in various Markdown flavors:
- Obsidian adopted similar highlight syntax (
==text==) - Task lists became standard in GitHub and GitLab
- CriticMarkup syntax is supported by MultiMarkdown and some editors
- No evidence of active parser/implementation
- Created as an academic exercise
- Most proposed features now available in other active flavors
- Helps preserve the history of the original comparison
The following flavors from the original 2021 comparison have been moved to archive status:
Status: Inactive (last update ~2016)
Notes: Ruby-based parser, largely superseded by Kramdown
Status: Maintenance mode
Notes: Python implementation, limited adoption compared to Python-Markdown
Status: Project deprecated
Notes: JavaScript parser, development ceased
Status: Limited maintenance
Notes: While still available, much less actively developed than other JS parsers
Status: Platform-specific
Notes: Ghost CMS uses their own Markdown variant, less relevant for general comparison
Status: Editor discontinued
Notes: Desktop editor, no longer maintained
Status: App-specific
Notes: Proprietary editor, less relevant for open format comparison
Status: Maintenance mode
Notes: Ruby library, largely superseded by other parsers
Status: Specification only
Notes: Academic proposal, no wide implementation
Status: Platform-specific
Notes: Project management tool's internal Markdown
Status: Platform-specific
Notes: Limited Markdown support, platform-specific
Status: Niche use
Notes: PHP library, limited adoption
Flavors are moved to the archive when they meet one or more of:
- No active development for 3+ years
- Superseded by another flavor
- Platform-specific with limited general applicability
- No parser implementation available
- Minimal adoption in the wider Markdown community
If a flavor becomes active again or gains significant adoption, it can be restored to the main comparison through a pull request with evidence of:
- Active development/maintenance
- Working parser/implementation
- Community adoption
- Updated feature documentation
Note: This archive helps maintain historical context while keeping the main comparison focused on currently relevant and actively maintained Markdown flavors. If you believe a flavor has been incorrectly archived, please open an issue with supporting evidence.