Logfilter is a tool for performing ad hoc analysis on Apache log files. Logfilter is especially useful when you wish to find records matching very specific criteria, since you can specify exactly which fields to match. The tool also plays well in a Unix environment by accepting input either through files or via stdin.
Testar is a tool that reduces testing time for large Java unit test suites. It runs on top of JUnit and automatically selects individual tests to execute based on changes made to the code since the previous tool invocation. It can be used both from the command line and inside an IDE.
Mr.Java is a Java IDE that is one step above a command line interface, but not quite as confusing as an IDE. It will compile for you, add libraries to your class path, and run the whole thing, with three simple buttons. Drag a library or Java source file over the window, and it will be put in the right folder. When running programs, the stout is written to a file cleverly named “stdout”, and the std err is cleverly written to file named - you guessed - stderr.
Poor Man's Imaging Wrapper a clean and simple API wrapper over JAI, Java2D, ImageIO, and AWT. It supports a set of imaging operations (read, write, scale/resize, crop, grayscale, add transparency, rotate, add border, flip/mirror, add text, overlay, blur, sharpen, etc.) with simple direct calls to the API. If you want to switch from Java2D to JAI, all you need to do is add JAI jars to the classpath. It supports GIF encoding if PJA tools jars are available in the classpath.