I have tried my hands on a few forum systems, namely - phpBB, VB, IPB & SMF. The new IPB rules the list, while phpBB is the best of the free ones.
Being Open Source and backed by a huge community, the possibilities with phpBB are endless. While the Gold version of phpBB2 lacks quite a few necessary features, most notably - Subforums and Attachments, you could be rest assured that there is a MOD available for every such feature. The upcoming version 3 of phpBB - Olympus will include most of the lacking features. Although, it has been stated that not all of the features will be included. After all, they are not trying to mimic other systems.
Olympus focuses on improved modularity. While the MODing of phpBB2 is pretty powerful, it does involve significantly high amount of complexity. Traditionally, MODs were installed manually rendering the process extremely time consuming. However, with the introduction of
EasyMOD, the inconveniance was greatly reduced. Huge MODs such as Subforum and Attachments leads to growing chance of collision between existing MODs. Olympus aims at resolving this issue by implementing a better modular approach. Coding styles have been altered and it is being said that none of the phpBB2 MODs will work with Olympus. This will hinder the initial spread of Olympus. As the developers start to chip in and start MODing it, Olympus will surely improve on the reputation, some amount of which was lost when the
Santy worm which exploited old phpBB installations came to the surface. The worm exploited the security hole by overwriting PHP and HTML pages. Olympus is also aimed at minimizing such vulnerablities.
Other features include, the debuting AJAX @ phpBB. However, the extent of AJAX usage will be limited and it is hinted that AJAX support will not be used for quick replies, perhaps due to security concerns. Adding Custom BBCode was quite difficult as the users had to rely on MODing. With Olympus such custom BBCodes can be added through the admin panel itself, much like what IPB allows. Users can now send Private messages to multiple recipients. Jabber support will allow notification via Instant Messaging. From what I saw of phpBB3 Beta 5, the installation has become much more user-friendly. The control panel seems better organized and the number of settings have increased.
For a wider list of introductory features in phpBB3, check out
http://www.freakitud...-new-in-phpbb3/All in all, if you are looking for a free discussion board for your site, there's nothing better than phpBB.