Markdown flavors7 min read
CommonMark, GFM, and GitHub Extended: choose the right profile
A decision guide to Markdown flavors, extensions, and the compatibility checks that prevent rendering surprises.
Read guideLocal-first workspaceCommonMark + GFM
Markdown stays honest from source to final page.
Write, preview, merge, and print Markdown in this browser—without hidden rewrites, an account, or format conversion.
No account required for editing and eligible local tools.
field-guide.md
SplitPreviewPrint
Saved1# Field guide
2
3Build a document that
4stays true from source
5to final page.
6
7- [x] Write
8- [x] Arrange
9- [ ] Publish
Field notes · 2026
Field guide
Build a document that stays true from source to final page.
- ✓ Write
- ✓ Arrange
- ○ Publish
No compatibility warnings
9 lines · GitHub Extended · UTF-8
Ln 9, Col 16 · UTF-8 · LF23 words · 0 warnings
No account required
Open, write, preview, and use eligible local tools. Files stay in this browser.
No silent rewrites
An unedited import can be downloaded byte-for-byte. After an edit, MDLoom encodes the current text using the recorded encoding and line-ending policy.
This browser only
Drafts stay on this device. Print uses your browser. Nothing is uploaded for writing, preview, merge, or print.
One workspace
Write, merge, and print in one place
The first release is a Markdown workspace: a source editor, a live preview, a file merger, and browser print. Conversion to Word and similar formats comes later.
Write
A source-first Markdown workspace
Edit raw Markdown beside a synchronized, sanitized preview. Ordinary editing does not run a formatter or parse-and-reserialize your source.
CommonMark · GFM · GitHub Extended
ExploreCompose
Merge files without breaking the document
Reorder chapters, shift headings, rewrite relative paths, and attach local assets to one portable bundle with file-scoped diagnostics.
Semantic merge · Source files unchanged
ExplorePreview, then print from this browser
Print mode shows the live Markdown preview on a page. Use your browser print dialog, and choose Save as PDF if you want a file.
This browser · no upload
ExploreSemantic composition
A book is more than files joined end to end.
Assemble manuals, handbooks, release notes, and long guides while keeping imported source entries separate from the generated result. MDLoom reports the joins it rewrites.
Explore Markdown mergeIllustrative team handbook
Example · 5 sources · 1 composition
- 1Clean
Introduction
01-introduction.md
- 2Clean
Working agreements
02-working-agreements.md
- 32 warnings
Engineering standards
03-engineering-standards.md
- 4Clean
Release process
04-release-process.md
- 5Clean
Appendix
05-appendix.md
Headings
Normalized
Links
18 resolved
Sources
Unchanged
Print in this browser
Preview the page, then print it.
Print preview uses the same Markdown engine as the editor. Your browser prints that preview. Page breaks, fonts, and margins can differ by Chrome, Safari, and Firefox. Choose Save as PDF in the print dialog if you want a file.
Open print previewPrint previewExample · A4
Team handbook
Working agreements
This browserNo uploadSave as PDF
Learn Markdown well
Guidance for the parts that usually break later
Short, reviewed guides about syntax, portability, composition, and print.
Publishing7 min read
Front matter for portable Markdown publishing
Define metadata ownership, merge policy, schemas, and destination mapping without leaking internal values into prose.
Read guideLearn Markdown8 min read
Markdown basics: a practical, portable foundation
Learn the small set of Markdown patterns that travel well between GitHub, documentation tools, and publishing workflows.
Read guideStraight answers
What MDLoom means by dependable
The important promises should be understandable before you trust the product with an important file.
Does MDLoom change my Markdown?
Ordinary editing does not run an automatic formatter. Unedited imports retain their original bytes; edited files are exported deterministically from the current text. Semantic merging creates a separate output and leaves its source entries unchanged.
How do I get a PDF?
Print preview uses the same Markdown engine as the editor. Your browser prints that preview. Page breaks, fonts, and margins can differ by Chrome, Safari, and Firefox. Choose Save as PDF in the print dialog if you want a file.
Which operations stay on my device?
Editing, preview, print, merge, and Markdown download run in this browser. Format conversion to Word or similar office files is not in this release.
Which Markdown flavor does MDLoom use?
GitHub Extended is the friendly default. Strict GFM, CommonMark, and a curated Pandoc publishing profile are selectable and versioned so the same source keeps the same interpretation.
Your source is the source of truth