Hi,

First official alpha release of Firekeeper - Intrusion Detection and
Prevention System for Firefox is available for download. Firekeeper
adds additional layer of protection to the browser. It uses flexible
rules similar to Snort ones to describe browser based attack
attempts. All incoming HTTP and HTTPS traffic is scanned with these
rules. HTTPS and compressed responses are scanned after
decryption/decompression. Suspicious response can trigger an alert that
is displayed to the user or can be automatically cancelled, depending
on an action specified in the rule. Firekeeper uses very effective
pattern matching engine from Snort and with well written rules doesn't
have a negative impact on the browser performance.

More information, screenshots and download links can be found at:
http://firekeeper.mozdev.org 
Project is GPL licensed.

Comments are very welcome.

Cheers,
Jan Wrobel