It might help a bit to know what OS you're on.
PostgreSQL runs natively on most flavors of unix, and comes as a standard package for most brands of free unix like freeBSD or RedHat or Suse.
If, however, you are running on Windows, you'll currently have to run it in cygwin to make it work.
There is a native port in progress, and it's very close to being done. Look for it this fall some time.
Why would you need Triad to run PHP/apache/MySQL together? They run fine together with no real need for a special package to make them get along.
