ChWP - by Petr Vavrinec

Available under GNU GPL license, this implementation uses a multi-thread server written in C and agent's process written in Progress 4GL.

Multithread server add some scalability
Works with earlier version of Progress – starting from v8
Basic functions available for development

OS dependent – Unix only
Problems in handling pipe communication mechanism between agents and broker
No web development environment available
Minimum compatibility with WebSpeed