4
don't think any1 will to be honest.. and if they do, support will be lacking and devs probly will get frustrated as before.. by the time you convert phpbb 2.0.20 to work with xoops, phpbb will most likely have found loads of other bugs/security exploits and will be on probably version 2.0.50, it was a never ending update all the time.. that's y development got scarce with it.
x-ipb is probably the better to go for..
well actually, ipb is loads more better than phpbb, it always has been, and is more secure..