Please help, I am confused

I don't know much about databasing and the communications involved but am
willing to learn.  I just need some clarification.  My host runs a CobaltXTR
and has Interbase6 SQL and PostgreSQL on a Linux2.2, Apache1.3.12 web
server.  It supports ASP by Chili!Soft CGI, Perl, PHP4, SSI, Java support
for JRE1.3, 128bit SSL and a few other things.

I want to setup a large discussion forum (similar look and feel to
vBulletin.com).  A lot of the discussion forums use MySQL, seems so popular,
is there some way to use my hosts IB6 to communicate or generate to a MySQL
format? How would this work out.  Kind of hard to find a "very descent
looking and feature rich" online forum that will communicate with IB6.

Another thing, I noticed in the IB6 docs it shows PHP with a database
connection to a file with the GDB extension.  I am assuming this is the IB6
format or something, though I don't have any software to open this or
generate a GDB format.

All this makes me confused, someone please help.

Thanks a bunch,
Ray