- http://www.eclipse.org - One of the most complete IDE's around with a lot of very interesting plugins.
- http://www.eclipse.org/webtools/index.html - If you ever need to do some J2EE project, this is the free plugin to try first.
- http://www.xmlbuddy.com/ - Nice xml plugin, there is a free as well as a pro edition.
- http://www.omondo.com/ - A UML plugin that is very easy to use, there is some database modelling as well, have not tried it so far.
- http://quantum.sourceforge.net/ - A database plugin with the most easy tasks available.
- http://www.eclipseide.com/ - A set of plugins for database access, uml modellinge (roundtrip), web development, J2EE services, etc. Works very good, it is not free (only $29,95).
- https://rome.dev.java.net/ - Rome is a component that enables you to create your own Rss feed and to read rss feeds from others in a java application.