I've been a professional Java developers for about seven years. Recently, I've spent my weekdays doing Android development.
In the past, a big programming interest of mine has been rule engines. I've worked quite a bit with both JBoss Drools and Sandia National Labs' Jess. Drools is my favorite by far.
And in my spare time, I've been working on a side-project using Apache Wicket (my favorite for web development), Spring, JPA/Hibernate, JMS/ActiveMQ, Joda Time, SASS (Syntactically Awesome Stylesheets), Quartz and so on... basically, all of the cool and/or popular stuff.
Q&A for professional and enthusiast programmers
Q&A for computer enthusiasts and power users
Q&A for enthusiasts and power users of the Android operating system
Q&A for professional programmers interested in conceptual questions about software development
Q&A for professional system and network administrators