''' this part is deprecated since [[Firefox]] use Web-Extenstions and [[Thunderbird]] Mail-Extensions'''
You can get more information at the [[DebianWebextensionTeam|Team-Site]]

= Policy for packaging extensions for XUL based applications =
''This is a draft and up for discussion on pkg-mozext-maintainers@lists.alioth.debian.org'':

== Filesystem Placement and Linking ==

The unpacked extension directory should be symlinked into the applications directory of every XUL application that can use the extension.  For example, the package for an extension "adblock-plus" (em-id `{d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}`) which works with Iceape (app-id `{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}`) and Iceweasel (app-id `{ec8030f7-c20a-464f-9b0e-13a3a9e97384}`) should drop links into both `/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/{d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}` and `/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/{d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}`, each pointing to the unpacked extension directory.  The extension can be installed directly into the applications directory instead of symlinking it if the extension supports only one XUL application.

== Package Naming ==

The binary package's name should be ''xul-ext-<ext>'' with ''<ext>'' being the extension's name. E.g. xul-ext-nostalgy for Icedove's nostalgy extension. The source package's name should be ''<ext>'' or ''<ext>-extension'' if the name is too generic. E.g. adblock-plus, nostalgy, notify-extension.

In order to ease finding extensions for a given application the packages
should 
{{{
Provides: <xul-based-app1>-<extension>, <xul-based-app2>-<extension>, ...
}}}
and
{{{
Enhances: <xul-based-app1>, <xul-based-app2>, ...
}}}

where xul-based-app1 and xul-based-app2 are e.g. iceweasel and iceape.

Rationale:
 * canonical place to look for extensions in the filesystem instead of having them spread across several directories (iceape, iceowl, icedove, iceweasel, ...)
 * consistent naming (visual grouping) for all extension packages (no ''mozilla-<ext>'' vs. ''iceweasel-<ext>'' for extensions supporting more than one XUL based application)
 * eases automatic packaging of extensions
 * ease work for downstream distributions which might use upstream's trademarked names for the XUL apps (e.g. if Ubuntu distributes "firefox" packages instead of "iceweasel", they can continue to ship xul-ext-fubar).

== Config Files ==

Note that many extensions contain default preferences files (e.g. `defaults/preferences/fubar.js`).  Site administrators may want to override these preferences for their users, so they should be treated as conffiles.  The simplest way to do this is to place an empty file under `/etc/xul-ext` (e.g. `/etc/xul-ext/fubar.js`), and create a symlink from `defaults/preferences/000system.js` in the unpacked xpi tree pointing to the file under `/etc/xul-ext`.

== Implementation/Tools ==

It is recommended to use [[mozilla-devscripts]]. It will realize the policy for you.