Simple Machines Forum is a free forum application. Simple Machines Forum forked from YaBBSE in 2003. Simple Machines Forum (SMF) is a next-generation community software package that is jam-packed with features, while at the same time having a minimal impact on resources.

Features:

• Advanced permission and user management.
• Tracking of new and old unread topics, not just from your last visit.
• Package manager that automatically installs or uninstalls mods (also known as hacks.)
• Major actions are time and IP locked, preventing 'hammering'.
• Create child boards under other boards. (sub boards)
• Configure permissions for each membergroup on the board level.
• Both cookie and session based authentication (works without cookies.)
• Ability to choose sendmail or SMTP (with or without authentication.)
• Assign several membergroups to a single member, with one membergroup as the primary group.
• Support of wildcards for email address, IP address, and hostname.
• Include an expiration time for bans.
• Export forum data using XML/RSS.
• Support for WAP, WAP2 and I-mode protocols.
• Members can choose which smiley set they wish to use (or none.)
• Spell Check, Quick Reply, WYSIWYG, 'Insert Quote', and other editing features.
• Polls can be added or removed to existing topics.
• Attachment filenames can be encrypted to increase the security (so you can upload .php files, etc.)
• Ability to allow members to use moderation on just topics they posted.
• Ability to Merge/Split topics.
• Recycle bin/board for all deleted topics and posts.
• Options to hide other members' avatars and signatures.
• Advanced user resources, including the ability to show new replies to your posts.