Woho! Bug 379633 is fixed!
ZipWriter just has been included into trunk.
You may say it’s a small thing. Who cares? Opera, IE, Safari lives without it and you can rarely see users complaining that their browser lacks scriptable zipwriter, right?
Hah! Mozilla is a platform, not “a browser”. It *does* influence any effort towards Xul editors, Mozilla IDE’s and… L10n tool 😉