Forums

https://mylittleforum.net/

https://www.minibb.com/

miniBB® is a standalone, open source program for building your own Internet forum, it's free to download and highly customizable.

http://www.funkboard.co.uk/

FunkBoard, the FREE full function multi-thread, highly customisable, open-source bulletin board messaging system. It uses the powerful PHP language and either MySQL or PostgreSQL database.

http://fudforum.org/forum/

https://fluxbb.org/

http://www.phpwebscripts.com/free-scripts/board_plus.html

http://www.anelectron.com/

https://www.beehiveforum.co.uk/

a PHP/MySQL discussion forum, and generally the best thing ever. Apart from real bees.