On many platforms, DrJava can be started by simply double-clicking on the .jar file you downloaded. DrJava can also be started from a command prompt, where you can optionally give it a list of source files to open at startup:
java -jar drjava-RELEASE-DATE-rREVISION.jar [-config [CONFIG_FILE]] [filename.java...]
Replace RELEASE-DATE-rREVISION with the appropriate value for your version of DrJava, e.g. java -jar drjava-stable-20080904-r4668.jar. The "config" argument is optional and allows you to specify a custom configuration file, rather than the .drjava file stored in your home directory.
Running DrJava on Mac OS X. If you are using Mac OS X, you can download DrJava as an Application from our website. Download the drjava-RELEASE-DATE-rREVISION-osx.tar.gz file and decompress it. You can then copy the DrJava icon into your Applications folder or keep it on your Dock.
Running DrJava on Windows. If you are using Windows, you can download DrJava as an executable file from our website. Download the drjava-RELEASE-DATE-rREVISION.exe file. You can then run it like a normal Windows program.