Forum OpenACS Q&A: Re: Hello! New to AOLServer and OPENACS. Question...
There is some interest in refactoring a bunch of the OpenACS Tcl code (e.g., the database API, templating system, and user authentication) to make it easier to use in non-OpenACS AOLserver environments, but currently it's not especially easy to do, and it definitely won't work that way out of the box.
So unless you have unusual or extreme requirements (e.g., an application server with no human users and which must not use a database at all), I recomend just installing the OpenACS core and using it, rather than trying to extract medium-sized chunks of functionality from the toolkit in order to use them stand-alone in AOLserver.
Once you are more familiar and proficient with OpenACS, you will probably see for yourself those few applications where you really might be better of just using some code taken from OpenACS, rather than installing OpenACS. But those areas are probably much fewer than you'd at first think, and hardly anyone does it, so you should definitely start out with the "mainstream" path of installing the OpenACS core and using it.
I have installed ACS, and it is really a wonderful thing. I san see many hard years of work here.