OpenIM is a Java implementation of a Jabber server. It is a complete rewrite of the Jaba Server project, and it supports the Jabber server to server communication protocol. It also supports Presence, Message, and Roster. Persistent storage is done in an XML file using XStream lib. It has been tested successfully with many clients such as Exodus, Rhymbox, GAIM, Psi, Greenthumb, and the Kopete.
POMStrap is a little library whose purpose is to solve the Java JAR hell problem. It works as an application bootstrap that builds a classloaders tree based on Maven 2 dependencies declared in project files (pom). Using POMStrap allows you to execute an application depending on multiple versions of a library without any conflict.