Authentic is a full-featured Liberty-compliant identity provider aiming to address a broad range of needs, from simple to complex setups. (GNU GPL)
IdPC is a minimalist Liberty identity provider written as a set of CGI scripts using Lasso. (GNU GPL)
Liberate DAV! is a free (GPL) Liberty Alliance ID-FF single sign-on module for WebDAV Apache2 servers.
Lasso is used in the French "Carte de Vie Quotidienne" and "Services de Vie Quotidienne" projects; the Lasso Python bindings are used to run the identity provider (macommune.identification.svq.fr) and two service providers (macommune.formulaires.svq.fr and macommune.consultation.svq.fr). The straight C library is used in the home-banking service provider.
Souk is a Liberty Alliance framework written in Python. It served as test platform to pass the Liberty Conformance event. (GNU GPL, no longer maintained).
Free (GPL) PHP code, that was initially designed to ease implementation of Lasso in services providers: LASSO Service Provider Kit. This "kit" is no more maintained.
SourceID is an open source (custom license) implementation of the Liberty Alliance ID-FF 1.2 protocols in Java.