Sun Microsystems has open-sourced the code for its implementation of JavaServer Faces (JSF), its framework for building user interfaces to Java-based web applications.

"JavaServer Faces has had external contributions, and this open-source strategy will make it easier to get contributions into the technology," Sun developer Roger Kitain, JSF's co-specification lead, wrote in his blog announcing the code release. Sun is placing the code under its Common Development and Distribution License (CDDL).

Sun's latest builds of its JSF 1.2 implementation, which the company calls "mostly stable," live on's GlassFish project page. GlassFish is Sun's open-source application server development initiative. Sun set Glassfish loose under its CDDL earlier this year, at its JavaOne conference.

Sun has been increasingly adding to its list of open-source projects this year as it looks to revive developer interest in its software stack. Last month, it launched OpenSSO (Open Source Web Single Sign-On) to encourage developers to work on application security using authentication and single-sign-on technologies.