4. Vanilla
At number four on our list of best easiest free forum software solutions, we have Vanilla that is one of the most widely used (by more than 414,000 communities) and best free forum software solutions mostly because of its simplicity. The simplicity of this software reflects in the way forum is managed – simply new messages appear on the top and stay if gain popularity, while there are no sub-categories. Good thing about this software is that it enables installing many plugins such as various smileys or Facebook.