I'm new to FileMaker Server, so maybe this is a simple question, maybe not. I've developed a FileMaker program for a non-profit group as a stand alone, one desktop program. Now I've been informed that they wish to run this program off their server. Since only a few people may be using this program at any given time, do they have to purchase FileMaker Server or can FileMaker 6 handle it? I know you can peer-to-peer the software, but that's one area I haven't dealt with. Thanks.

If you mean you developed RunTime, then only FM server can host that.

If you unlock the solution, FM client can run that also.

I'm running a solution with peer-to-peer networking that has 5 simultaneous connections, and it works fine. I don't know how many more you can really handle before it starts to slow down, and since I don't have any more computers (or any more FMP licenses) I can't test this. I've heard that ~10 might be the upper limit for peer to peer

Really 5 is the upper limit, after that things get real unstable real quick.

Do I need to make any tweaks to my RunTime program in order to adapt it to be used on the server? Or will it work "as is"? Thanks.

IMHO -- set in FM server (register) the extension you are using and it should work. Some things will work differently e.g. global fields. Just short time ago there was topic for differences between single and multi-user usage.