What is "punbb"

PunBB (PunBulletinBoard) is a lightweight PHP-based internet discussion board system. It is released under the GNU General Public License. The project's primary goal is to be a faster, smaller and less graphic alternative to discussion boards such as phpBB, Invision Power Board or vBulletin. Many open-source and commercial projects' discussion boards use PunBB. Until September 2011, Facebook's Developers were using Facebook Developer's Forum for discussions and bug reports, which was powered by PunBB.

PunBB was originally designed to output standard XHTML, and with speed and simplicity in mind. Features such as private messaging, polls and file attachments were not originally implemented. However, they have since been released as third-party modifications. PunBB supports extensions since version 1.3.