You can have a look at Products.Ploneboard
or collective.ploneboard
. Both are simple solutions supporting only the basic forum functionalities: creating forums, creating discussions in a forum and participating in those discussions by creating replies to messages.
Products.Ploneboard
is based on Archetypes
, the main content framework up to Plone version 4 (from Plone version 5 on, its main content framework is dexterity
). It is likely not yet adapted for Plone 5. collective.ploneboard
is a partial reimplementation of Products.Ploneboard
on top of dexterity
; it may be a better fit for Plone 5.