A project Open Icon Library (http://openiconlibrary.sourceforge.net/) will be very useful for the developers / designers to use icon free, modify and redistribute. I found it very helpful to community and some how everybody in this community need icons either they are web designers or application developers.
A free and open Icon collection. Over 10,000 Unique Icons. Free for anyone to use on you computer, website or any other project. The library is not a theme. Its a centralized source for icons to cover all your needs. The goal is to cover all common apps, operating systems, mimetypes, devices, and country flags.
The icons includes application icons, flags, devices, OS etc, full list can be viewed at http://openiconlibrary.sourceforge.net
You can download them as Icon Package or Webapp Package and used them as per your need.
There goal is to
Offer a consolidated source of icons for people to custimise there desktop, as they wish, without relying of a single theme.
Happy designing/developing.