The Firefox team has decided to discontinue support for SSL 2.0, and only support SSL 3.0 and TSL 1.0. SSL (Secure Sockets Layer) is basically an encryption protocol that provides security for internet connections; it's what creates that little "lock" icon at the bottom of your browser.
Janz was slightly miffed by my excitement over this seemingly trivial news. Let me explain: the SSL 2.0 protocol has been outdated and vulnerable for years (SSL 3.0 was introduced in 1996 by then browser-king Netscape). However, a number of websites still use the old protocol.
The effect of Firefox's discontinuation of support for the SSL 2.0 protocol is it effectively puts pressure on web administrators and designers to upgrade to SSL 3.0 or TSL 1.0, and such pressure will only increase as more users (hopefully) flock towards Firefox.
You can disable SSL 2.0 in Firefox with current versions by going to Tools>Options>Advanced and unchecking Use SSL 2.0 under Security
(What is SSL and TSL?)
Read: Mozillazine announcement
Tags: mozilla, firefox, ssl, tsl, encryption