pl/pgsql and global variables

Hello,

We are trying to select which procedural language to use with postgresql. We
are familiar with oracle and PL/SQL and were pleased with the close match
with PL/pgSQL.

However we need access to global variables in PL/pgSQL. I cannot find any
mention of this in the docs. A search on google was not helpful as it just
pointed back at the docs. Is this feature available, or do we have to use
some of the other available languages such as PL/TCL or PL/Python?

Also any advice on the stability of any of the PL/languages would be
appreciated.

Thanks again for reading and answering this.

John Lim