open source is no more a security risk than the extreme proprietory platforms such as what Microsoft has been capapble of.

Before "leaving office" Bill Gates wrote the famous memo "beware the internet tidal wave".

(And in my opinion, at that time- Miguel de Icaza)

However the key lineage in that memo is "internet" and the push to get everyones OS online.

Google is a big example of that. (Google Docs etc)

But the next word in the lineage of "internet" is website.

And so there, it is up to the name of the group or person who owns the website to decide on their security risks with which platform they will choose (yay Rails!!)

Also, today, the best websites use incredible amolgamates of pre-existing platfroms but with an intense "re-visit" into the guts of that code for the sake of longevity and scalablilty. Then they decide whether to scrap-it or salvage some or all.

("Re-design my core!")

One of my favorite examples is Pandora.coms core technologies:   

"Linux, PostgreSQL, Slony, Database Administration, Python, Distributed Systems."

from: http://blog.pandora.com/jobs/

It clearly looks like a cross platform though Pandora now runs on AIR (Adobe).

Hackers and Crackers know how to deal with both cross platform vulnerabilities (and their inter-connectivity) as well as a stand-alone tank.

Neither is 'mo betta' than the other in the case of a security risk.

I found this at the last minute sorry: "Pandora is currently for US listening only."