This is where you find the most recent online documentation for Roxen WebServer 4.5, besides the one shipped in the distributions:

This is where you find the most recent online documentation for Pike 7.0 (also shipped with Roxen distributions):

We keep a back record of documentation for previous non-commercial versions of Roxen for online browsing in our archive. You may also download a daily updated version of the manual in the format used by the WebServer administration interface of your existing installation.