zac4firefox is a Firefox extension that restrict the actions that can be performed by the scripts of pages visited by the user.

The extension can be downloaded from here.

• Due to the performance penalties introduced by the transformation phase required by AspectScript, the observable overhead ranges from acceptable to very high, depending on the load of JavaScript computation of the visited page
• Due to the limitations introduced by the parser used by AspectScript (the parser from the Narcissus project), some scripts are not transformed, and therefore are not subject to ZAC policies. Then this occur, a notification is presented to the user.