Fastmail vs Zulip

Fastmail (Open-source software developed at Fastmail.) and Zulip (Organized team chat) both appear on the Smoower Developer Ecosystem Index.

Fastmail (rank #430) holds a narrow lead over Zulip (rank #536) on the overall Smoower ecosystem score (40 vs 36). The gap of 4 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), Zulip is clearly ahead of Fastmail. On education (docs, guides and learning material for developers), Fastmail is ahead of Zulip. On community (issue response, PR reviews and discussion health), Zulip is ahead of Fastmail. On reach (how visible the ecosystem is beyond its own repos), Fastmail is clearly ahead of Zulip. On momentum (release cadence and how fast the ecosystem moves), Fastmail is slightly ahead of Zulip.

Fastmail carries 6,316 GitHub stars across 38 public repos, with 12 repositories active in the last 90 days and 2 external contributors on record. Zulip shows 32,299 stars across 67 public repos, 9 active in the last 90 days and 76 external contributors. The star gap on its own does not decide the comparison, but Zulip's footprint is roughly 5.1x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Fastmail is the stronger read for anyone weighting reach. Zulip looks better where code quality is the deciding factor. The table below breaks the scores down pillar by pillar; the linked profiles cover the underlying repos, docs and community signals in full.