Forum OpenACS Q&A: Re: Best way to do HTTP 3xx Redirections?
Using a registered proc is the traditional AOLserver way to do this. (Philip talked briefly about it in Chapter 10 of his book.) The way to go is probably either adding some kind of hook to the request processsor, or running something either immediately before or after the request processor. (E.g., when you would otherwise serve a 404 Not Found call your redirection stuff instead.) You might want to take a look at the old Redirecte code (it's less than 300 lines) and see about tying it into the request processor somehow.