Free forum
The ProjectForum software runs as a server application on a central server or your own computer, and you and others use your web browser to connect to the software, the same as you would any other web site. All regular use by you or your users therefore is done via any standard web browser (IE, Netscape, Safari, Opera, etc.) running on any platform.

The software is designed to be able to run on your normal desktop computer if you want; you do not need to have special "server" hardware (though you can certainly put it on a server if you have one available), existing web server software, etc.

The computer you run the software on should be regularly connected to the network (e.g. have a static IP address/name), be able to listen on port 3455 or another port such as 80, and at least 5mb of free disk space (though you'll want more as your groups use ProjectForum).

The server software will run on any machine running Windows 98/ME/NT/2000/XP, Mac OS X 10.1 or higher, Linux (kernel 2.2 or higher), or FreeBSD 4.5 or higher.