Fastmail vs SlackAPI

Fastmail (Open-source software developed at Fastmail.) and SlackAPI (https://docs.slack.dev/tools) both appear on the Smoower Developer Ecosystem Index.

SlackAPI (rank #47) holds a meaningful lead over Fastmail (rank #430) on the overall Smoower ecosystem score (61 vs 40). The gap of 21 points reflects composite signals across code, docs, community and reach.

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

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. SlackAPI shows 17,894 stars across 37 public repos, 19 active in the last 90 days and 39 external contributors.

Fastmail is the stronger read for anyone weighting reach. SlackAPI 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.