This is Web Processing Service (WPS) community page, developped by Graham Davis and Lucas Reed:

This WPS module makes use of the GeoTools Process and WPS modules, and has been tested with the recent GeoServer WPS addition.  It adds support for WPS services to the catalog and also adds a new view for executing processes on a WPS server.

For instructions about installing and using this community plugin, please check out the WPS community pages.