Do you have trouble keeping track of your disk usage? Do you sometimes need to free up space, but have no idea what to start deleting? Have a look at jDiskReport, which is a Java application written by expert programmer Karsten Lentzsch of Kiel in Germany.

jDiskReport is a free cross-platform graphical disk report utility. It lets you understand how much space the files and directories consume on your hard disks.

Figure 1-2 shows jDiskReport but really doesn't do justice to the program.

Figure 1-2. The jDiskReport: keeping track of hard disk space.

The jDiskReport software is freely from Karsten's website at www.jgoodies.com. Download it and unzip the file. There is a readme.txt and a jar file. Go to the directory containing those files, and start the program with the command line

The application will summarize the disk usage on your system and display it in a large variety of formats: oldest, largest, by type of file, pie chart, bar graph, text, tree display. This software was written once, and it runs on Linux, the Mac, Solaris, an HP Risc system, and so on. It is a very user friendly program, fast, and a good advert for the Java GUI library known as “Swing.” Karsten has additional Java software on his website, too. If someone tells you that Java is only good for server software, show them this desktop application. Try it yourself; you'll probably find it very useful.