PGP and GNUpg

[Kailash Kayastha <kkayast () abcv com>]

Hello,
I have very little knowledge on encryption technologies. We have been using
PGP for windows for past few years. We are thinking of moving towards GNUpg
on Solaris 8.  Does anyone know if GnuPG is any less or more reliable and
secure than PGP? OR is there any other free reliable/secure encryption
solutions available?
Thanks,
Kailash