Some quick feedback. It seems to me most of the documents are quite high quality and actually mostly still accurate since the basics haven't really changed. However, the APM doc in the packages guide (developers guide)
http://aufrecht.org/doc/packages.html
has a couple of small inaccuracies that I am to blame for. File listings in info files are not used anymore. Also, there are new file types for Tcl tests. The doc should make mention of APM callbacks.
It might make sense to weed out all references to ArsDigita (not least the email addresses!). I mean it does feel weird when the doc says that "we at ArsDigita" currently do things this or that way.