Fastmail vs Sage

Fastmail (Open-source software developed at Fastmail.) and Sage both appear on the Smoower Developer Ecosystem Index.

Fastmail (rank #430) holds a narrow lead over Sage (rank #625) on the overall Smoower ecosystem score (40 vs 33). The gap of 7 points reflects composite signals across code, docs, community and reach.

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

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. Sage shows 2,180 stars across 122 public repos, 6 active in the last 90 days and 22 external contributors.

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