That website is hilarious. I was on there a long time ago. While the Masons were traditionally VERY anti-Catholic that has faded over time and it is like any other fraternal organization- Guys having an excuse to get away from their wives for a little while.
I wouldn't exactly call it anti-Catholic, since PA State Senator Vincent Fumo is also a Freemason. He's also a member of the Knights of Columbus and Mensa. So was former PA state senator Frank Pecora, whom I've met, who is also Catholic.
One can't be a Catholic and a Mason, since the Catholic church still prohibits membership. So if you join, you are basically excommunicated. This is one of the few issues I agree with the Catholic Chuch on.