Prefer this fork if your priority is Thunderbird continuity and active revival work. Prefer upstream if you want the broadest, best-traveled browser-extension path and less divergence risk.
jlegewie/markdown-here
stale
significant_divergence
Prefer this fork only if Zotero integration in an old Firefox-style environment is the goal. For general Markdown Here use, upstream is a far better choice because this fork is stale and materially behind.
Prefer upstream unless you explicitly want an old baseline to maintain yourself; this fork adds no apparent value beyond being a stale copy.
Prefer upstream unless you specifically need the fork's code-highlight formatting or already depend on it; the fork is much older and likely misses substantial fixes and modernization work.
Prefer this fork only if you need the math/macro/Zotero-oriented rendering changes. For general Markdown Here usage, upstream is the safer choice because it is much more current and has ongoing maintenance work that this fork lacks.
Prefer upstream unless you specifically need this repository namespace or ownership model. This fork adds no visible product value and is already 45 commits behind upstream, so adopters inherit upstream behavior without the newest maintenance and compatibility work.
Bubbablack/markdown-here
stale
significant_divergence
Prefer upstream unless you explicitly need a frozen 2020 snapshot. This fork shows no added capabilities, is materially stale, and misses recent upstream maintenance and compatibility work.
blasten/markdown-here
stale
significant_divergence
Do not choose this fork for normal use. It offers the same core feature as upstream but is far behind on maintenance and modernization, so upstream is the clear default unless you specifically need an old frozen snapshot.
Prefer upstream for normal use. Choose this fork only if you need a frozen 2017-era snapshot and are willing to own all maintenance yourself.
Choose upstream unless you specifically need this fork’s older snapshot. It adds no visible capabilities, while trailing upstream by 45 commits means missing recent fixes and cleanup.