PWS is the Pegasi Web Server, written from scratch in Java.
The project started as a project for the course of Networking at the Hogeschool Gent, by members/founders of the PegasiLUG.
Everything is documented in the distribution archives. Please check there.
Any 100%-compatible Java Runtime Environment (this _excludes_ the Microsoft VM!).
A computer with TCP/IP networking installed. (nearly always the case)