Factorial vs Fastmail

Factorial (HR Software for small and medium companies) and Fastmail (Open-source software developed at Fastmail.) both appear on the Smoower Developer Ecosystem Index.

Factorial (rank #237) holds a narrow lead over Fastmail (rank #430) on the overall Smoower ecosystem score (48 vs 40). The gap of 8 points reflects composite signals across code, docs, community and reach.

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

Factorial carries 117 GitHub stars across 70 public repos, with 19 repositories active in the last 90 days and 53 external contributors on record. Fastmail shows 6,316 stars across 38 public repos, 12 active in the last 90 days and 2 external contributors. The star gap on its own does not decide the comparison, but Fastmail's footprint is roughly 54.0x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Factorial is the stronger read for anyone weighting code quality. Fastmail looks better where reach 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.