Fastmail vs Stream

Fastmail (Open-source software developed at Fastmail.) and Stream (Build scalable in-app chat, feeds, and live video with AI moderation capabilities in hours, not weeks.) both appear on the Smoower Developer Ecosystem Index.

Stream (rank #317) holds a narrow lead over Fastmail (rank #430) on the overall Smoower ecosystem score (44 vs 40). 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), Stream is clearly ahead of Fastmail. On education (docs, guides and learning material for developers), Fastmail is ahead of Stream. On community (issue response, PR reviews and discussion health), Stream is ahead of Fastmail. On reach (how visible the ecosystem is beyond its own repos), Fastmail is clearly ahead of Stream. On momentum (release cadence and how fast the ecosystem moves), Stream 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. Stream shows 35,664 stars across 487 public repos, 84 active in the last 90 days and 44 external contributors. The star gap on its own does not decide the comparison, but Stream's footprint is roughly 5.6x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Fastmail is the stronger read for anyone weighting reach. Stream looks better where momentum 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.