I decided to research forum converters and I was very surprised by how much coverage is out there. vBulletin leads the pack with the most converters available at one point or another. Note: Many of those listed may not longer be supported, particularly due to end of life of the other product, or lack of demand.
I've listed the supported importers, converters, and merge systems (they vary in naming from platform to platform) for vBulletin, IPB, myBB, xenForo, and phpBB. With the number of forums out there, this could really be the topic of an entire forum!
vBulletin
Importers (Members Area/Import download link)
ImpEx Systems with Modules for:
http://www.vbulletin.com/docs/html/impex_module_dump
Available:
ASPPlayground, CHC Forum, DCForum+ MySQL, DiscusWare 4.x Pro tab file data, InstantForum, Invision Community Blog, MxBoard, MyBulletinBoard (MyBB), Infopop Open Topic, PNphpBB2 (Post Nuke), Advanced Electron Forum, w-Agora, Allaire, ASP-DEV, BuildACommunity, bbBoard, bbpress, beehive, CFBB, Community Server, CuteCast, Deluxe Portal, DigiPost, DiscusWare (file based), Discuz, dotnetBB, dragonfly, Drupal, dzoic, e107, Edge CMS, EncoreII, eshare, Eve 1.3.4 / Groupee 4.0.3, ExpressionEngine, fireboard, freethreads, FUD Forum, FuseTalk, fusion BB, fusionBB 2, Geeklog, Ikonboard (MySQL), Invision Power Board, Invision Board 2, Invision Board 3, JForum, Jive, Jive Forums, Seditio (LDU), Max Web Portal, megaBBS, mercuryboard, miniBB, mmforum, mvnforum, mysmartbb, MyTopix, openBB, Oxygen, Phorum 3, Phorum 5, Photopost, phpBB1, phpBB2, phpBB3, phpMyForum, PHP Fusion, Phpwind, PunBB, Simple Board, SiteFrame, SiteNet BBS, Simple Machines Forum, SMF, Snitz Mysql, ThWboard, Toast Forums, Tritanium BB2, trollix XForum, TruBB, ttCMS, Text file importer, Infopop UBB classic, Infopop UBB.threads, Infopop UBB.threads, Ultraboard, versatile Bulletin Board, vBJournal, vBulletin Forum 2 Blog, vBlogetin, vanilla, vBulletin 2, vBulletin, vBulletin lite, vbzoom, WoltLab Burning Board, wbb3, webbbs, Webcrossing, Web Wiz Forums, WordPress, wowBB, XMB forum, Xoops - Newbb, Xsorbit X5, YaBB 2, YaBB Gold, YaBB SE, Yet Another Forum, Yahoo Groups access dB download, Yahoo groups (raw text), zeroforum
Note: Some are tier 3 and discontinued.
IPB Converters
http://www.invisionpower.com/suite/convert.php
Avaiable:
4images 1.7, bbpress, Community Server, Coppermine 1.4, Discuz, Dragonfly, e107, eBlah, FudForum, FuseTalk, FusionBB 3.0, InstantForum, MegaBBS, MyBB 1.4, Ning, Photopost 6.2, hotoPlog 2.x, phpBB 2.0, phpBB 3.0, phpFusion 6, phpMyForum 4.1, PunBB 1.3.4, simplepress, SMF 1.1 and 2.0, UBB.Threads 7.5, vBulletin 3.8, vBulletin 4.0, WebWiz 8.x, Woltlab BB 3.0, Wordpress, WowBB 1.7, XMB 1.9, Xoops, YAF.NET 1.9, ZenPhoto 1.2
myBB Merge System
http://www.mybb.com/downloads/merge-system
Available:
Invision Power Board 2.1, 2.2, or 2.3, MyBB 1.6 (Merge multiple copies of MyBB in to the one), phpBB 2, phpBB 3, SMF 1.1, 2.0, PunBB 1.2, vBulletin 3.6, 3.7, or 3.8
xenForo Importers/Converters
http://xenforo.com/community/threads/pre-sales-faq.4951/
Available:
vBulletin 3.6/3.7/3.8 importers built in
IP.Board 3.1.x importer built in
Unofficial vBulletin 4.0/4.1 importer available as an add-on
Unofficial PunBB 1.2/1.3 importer available as an add-on
Unofficial SMF 2 importer currently being developed
phpBB Converters
http://www.phpbb.com/customise/db/convertors-22/
http://www.phpbb.com/community/viewtopic.php?f=65&t=1641375
Available:
Categories Hierarchy, Drupal 5.x, IPB 1.3, IPB 2.3.x, Icy Phoenix 1.3.0.53a, myBB 1.4.x, Ning, Phorum 5.0.x, PHP-Nuke, United-Nuke 4.2.08ms2, PHP-NUKE 7.9, Nuke-Evolution Basic - 2.0.5, PHP Nuke Clan 4.2.0, SMF 1.1.x, phpBB2 with Simple Subforums, Proboards, SMF 1.1.x, SMF 1.1.x converter support topic, SMF 2.0RC.x, vB 3.x, Yahoo
Forum Importers, Converters, Merge System for vBulletin, IPB, myBB, xenForo, and phpBB
Admin
Topics: 130
Replies: 412
Note: Because vBulletin supports so many different conversions, they make it possible to do a two-step import process to other forums that import only vBulletin.
For example, vBulletin supports import of bbPress. Launch.forum plans to support import of vBulletin.
So if you first import bbPress into vBulletin, you can then import it into Launch.forum as such:
bbPress > vBulletin > Launch.forum
There may be some minor issues that make this non ideal because you are depending on the vBulletin impex converter to bring all of the bbPress data in correctly. However, vBulletin's excellent coverage with their importers opens up the chance for people otherwise stuck on lessor known forums to make their conversion to a new package like Launch.forum or xenForo. The only other alternative is a custom import process, and the involves complexity, time, and money (for those who cannot do the coding themselves, i.e. most people).
For example, vBulletin supports import of bbPress. Launch.forum plans to support import of vBulletin.
So if you first import bbPress into vBulletin, you can then import it into Launch.forum as such:
bbPress > vBulletin > Launch.forum
There may be some minor issues that make this non ideal because you are depending on the vBulletin impex converter to bring all of the bbPress data in correctly. However, vBulletin's excellent coverage with their importers opens up the chance for people otherwise stuck on lessor known forums to make their conversion to a new package like Launch.forum or xenForo. The only other alternative is a custom import process, and the involves complexity, time, and money (for those who cannot do the coding themselves, i.e. most people).
Hello, how does LF support user passwords? Do they need to be reset or will the hash + underlying logic be imported also.
Admin
Topics: 130
Replies: 412
We haven't started work on any converters for Launch.forum yet. Ideally, we could love to import a working password not requiring an immediate reset, at least for a limited time period. Anything to avoid user frustration or confusion on the move over. This part is tbd at the moment.
sairanjank
Jun 25 2011 14:45
What about MyBB>LF?
Admin
Topics: 130
Replies: 412
Converters won't emerge until after we're launched and had some time to a growing user base. All of the more popular forum software options out that are candididates for converters, based on demand. We're not really focusing on attention on that area at this time. Our primary concern is getting Launch.forum to "launch" readiness. =)
Sep 6 2011 23:22
by Pokeaura ikuto
Topics: 0
Replies: 1
Is there any way for me to convert my forum from PunBB to vBulletin? I'm using a forumotion free forum hosting site, and I have purchased the domain for http://www.pokeaura.net as well as have removed the forumotion copyrights. I just want to know if there is anyway for me to convert, because i like the layout and designs of vBulletin better than PunBB, PhpBB, and Invision....please help...! Thanks 
sairanjank
Sep 7 2011 16:08
I would suggest to wait till LaunchForum comes out. Its going to be fun!.
