Can the database of a phpBB forum be transferred across to run under vBulletin, without losing memberlists, post history and so forth?

Yes. Members, threads, and posts can be transferred over. The site's style / templates obviously cannot. Last I checked, private messages and, unfortunately, member passwords, didn't transfer over, however. The vBulletin developers recently released new conversion software, however.

you can using phpmyadmin/

The actual conversion must happen via the vBulletin importer available at www.vbulletin.com in, I believe, the announcements forum. phpMyAdmin as well as good ol' SSH can be used to back up and restore the database in the future (due to server moves, regular "just-in-case" backups, etc.)

Hi there,

We currently offer a professional import/export system called vBulletin ImpEx which allows users to move from their forum software to vBulletin - it comes with a import script for phpBB. More details obviously on the vBulletin.com web site.

Thanks for the clarification Floris

Is it possible to convert extremephpbb to vbulletin. I have a community forum with lots of attachments and I have been told that the converter with vbulletin dosen't convert something such as the attachment hacks.

I would check vBulletin.org. I remember hearing somewhere that someone wrote an onofficial add-in for the phpBB->vBulletin converter to support attachments.

No, I doubt it works, the phpBB (Extreme phpBB) is a pre-modded phpBB forum. Therfore, I doubt it'll work because of the additional database changes and modification changes and such. I may be wrong, so dont take my work for it.....

In my opinion a move from phpBB to vBull is a downgrade. Unless you don't do any coding at all and need a gob of support. The release of phpBB 2.2 (if it ever happens) will change the future of bulletin boards.