Checkout.com vs Fastmail

Checkout.com (A collection of libraries and plugins for Checkout.com) and Fastmail (Open-source software developed at Fastmail.) both appear on the Smoower Developer Ecosystem Index.

Checkout.com (rank #152) holds a modest lead over Fastmail (rank #430) on the overall Smoower ecosystem score (52 vs 40). The gap of 12 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), Checkout.com is clearly ahead of Fastmail. On education (docs, guides and learning material for developers), Fastmail is ahead of Checkout.com. On reach (how visible the ecosystem is beyond its own repos), Fastmail is ahead of Checkout.com. On momentum (release cadence and how fast the ecosystem moves), Checkout.com is ahead of Fastmail.

Checkout.com carries 542 GitHub stars across 55 public repos, with 26 repositories active in the last 90 days and 11 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 11.7x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Checkout.com 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.