PHP:
Advanced Electron Forum
bbPress
Beehive Forum
Drupal Forum
esoTalk
Extreme Message Board
FluxBB
FUDForum
FusionBB
IceBB
IP.Board
Joomla Forum
MesDiscussions
MiniBB
MyBB
Phorum
PhpBB 3
PunBB
Quicksilver Forums
SEO-Board
Simple Machines 2
SocialEngine
UBB.threads
UltraBB
Unclassified NewsBoard
UseBB
Vanilla Forums
vBulletin 4
Viscacha
Wikid Forum
Woltlab Burning Board
XenForo
Java / JEE:
JavaBB
JForum
MVN Forum
Yazd
Hosted:
Answerbase
BulletinBoards
ForumCommunity
Forumotion
FreeForums
Google Groups
Lefora
Nabble
Ninja Post
NitPick 2011
ProBoards
Tal.ki
Twelvestone
Website Toolbox
ZetaBoards
Zoho Discussions
Microsoft .Net:
Comm100 Forum
NearForums
Yet Another Forum
Perl:
YaBB