The Earth Alliance funded the first...

 Posted on 5/1/1994 by STRACZYNSKI [Joe] to GENIE

The Earth Alliance funded the first few attempts exclusively; after
they'd dumped all their money into B4, they needed outside funding to get B5
going, and the Minbari were first to contribute money as a show of good faith.
Then the Centauri added additional funding. Those are the only two other
races that've contributed significantly.

The world B5 orbits is Epsilon 3.

PPG = Phased Plasma Gun.