PostgreSQL most definitely works great on Solaris x86 !
At UC Berkeley, we have our undergraduate students hack on the
internals of PostgreSQL in the upper-division "Introduction to
Database Systems" class ..
http://www-inst.eecs.berkeley.edu/~cs186/
The "official" platform is Solaris x86 - that's where the students get
accounts and they have to get their code working on that platform as
the TAs will only test and grade their submissions on Solaris x86.
(Besides, I also got TelegraphCQ running on Solaris x86 .. just for
kicks though .. and TelegraphCQ is based off of pgsql-7.3.2)
--
Pip-pip
Sailesh
http://www.cs.berkeley.edu/~sailesh