BaseX is very light-weight, easy to use, and runs out of the box!
It is completely written in Java 6 and has been tested and optimized for various platforms. The GUI and the Server are bundled in a single file, including all APIs, start scripts and sample documents.

Windows Installer | ZIP Archive | Mac OSX | JAR Core Library | WAR Application |
Please note that the GUI and the Client/Server architecture of BaseX are not synchronized. You may encounter unexpected behavior, and your databases might even get corrupt, if you update from BaseX instances that run in different Java VMs.