simple forum with security

I'm thinking of adding a forum to my website.
I see a lot of forums getting hacked lately.
PHP forums seem to be the standard now but are they more secure than a perl forum?
What is the safest solution?
Cost is a factor.

The language shouldn't really dictate the security.

Make sure you pick a forum with a decent number of developers and you can be fairly well assured that fixes will be available quickly.

Although there have been quite a few exploits against phpBB2 it is pretty good and security fixes are usually available quickly.

i've had good luck with http://www.minibb.net/ Much smaller feature set and foot print than other forums but seems to be more secure.