Passwordless (by Bitwarden)
A passkey software toolkit for developers
Details
The server part of Passwordless is provided under a custom BITWARDEN LICENSE AGREEMENT which sets many restrictions relative to what’s expected from FOSS.
The project does however market itself as open source in many areas:
“All Passwordless.dev code is open source.” - In the project docs.
“The open source offering saves engineering resources and […]” - Marketing Blogpost
“Thorough, third party assessments of the Bitwarden Passwordless.dev open source code […]” - Product Homepage (although could be indicating their only the open source work is assessed, a little unclear)
Many of the Passwordless client libraries are open source, but these appear to require use of the server component.
Bitwarden has taken at least $100m in funding from PSG and Battery Ventures.