I am a member of 2 forums, this one and one that is specific to my little dog which is a miniature Schnauzer puppy. The dog forum was hosted by the Schnauzer Club of Great Britain but for some reason they have decided to close it (liability over vet. advice etc.)

We are a sad bunch who get quite excited when our dogs eventually crap outside but they were a good group and it was quite a lively forum.
My question is, what would be involved if I wanted to set up a forum to replace the closed one? Is there any bulletin board type software that is available as "open source"? I know it would have to be hosted somewhere but I don't think that is a problem these days. I think most of the members would be happy to spend a few quid to keep it going and I would imagine that once it reached a certain number of members it would probably be able to attract advertisers.
I wonder if Chris wants to expand this forum with a Schnauzer sub-forum??