OpenSwing is a components library that provides a rich set of advanced graphics components for developing desktop applications and HTTP/RMI based java applications/RIAs based on Swing front-end. It provides also adapters for Hibernate, JPA, iBatis, etc.
Almond Java Application Framework is an easy to use Swing based framework for Java applications. Almond is very much inspired by the K Desktop Environment.
FotkaAPI is free library written in PHP at GNU GPL license. This lib allows many useful things related with community-portal fotka.pl
JGGAPi is java implementation of Gadu-Gadu protocol. Gadu-Gadu is a IM system very popular in Poland based on proprietary protocol. The implementation is based on specification of Gadu-Gadu protocol gathered during implementation of EKG application.
OtrosVfsBrowser download page
Since Google code is not supporting downloads, downloads can be found on sf.net.
Wix is the library similar to Objects in early Borland TurboPascal, which allow you to create windows containing buttons, textboxes and so on, using only text mode.