WeirdX
- An X Window System server in pure Java. [Open source, GPL]
- http://www.jcraft.com/weirdx/

s-integrator
- A "light-weight", adaptable integration server that rapidly integrates services from various systems.
- http://www.s-integrator.org/

Saffron Document Server
- An all-Java, high concurrency Postscript interpreter and family of output modules. It generates PDF, HTML, RTF, TIFF and other file formats.
- http://www.dynalivery.com/products/saffron/saffron.html