PhpBB is still one of the best existing open source forum software.
The PhpBB huge community, that provides help, tons of plugins and themes
will always provide a solution to any people interested in installing and using PhpBB.
The Simple Machines license explains that this software could not be redistributed without explicit SMF developers agreements. So we could not consider it as a free and open source software, but as a freeware only.
This will not prevent us having a really good opinion about this really software,
which can easily be compared to best existing open source software. Its robust source code and its impressive and dynamic community easily convince beginners and advanced users to install it.