FotkaAPI is free library written in PHP at GNU GPL license. This lib allows many useful things related with community-portal fotka.pl
OtrosVfsBrowser download page
Since Google code is not supporting downloads, downloads can be found on sf.net.
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.
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.
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.
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.