Is there a genral programmers guide (formal or informal) on how to add a new datasource (compressed files) and crawler ((s)ftp)?


I thought I would ask since the documentation I have read through so far has been excellent and someone may have already written this or have an old email on how to do it.


I would like to add (s)ftp but I am not sure if that falls under a new one from scratch (and wanted to make sure I knew all the areas to work in to develop it correctly) or would it be part of extending the web one (which does http(s) already).  I feel it is the former.