Open Icon Library
- Open Icon Library has a huge gallery of free icons under various licenses, including commerical-friendly licenses.
Tango Desktop Project
- Icons are offered under the Public Domain license, can be used within open source and commercial applications.
- Has a consistent look & feel across the same set of icons.
Glyphish
- Glyphish provides 200 free icons under Creative Commons Attribution license.
- For $25, you can get additional 60 icons without the attribution license.
Help keep this page a valuable resource to everyone. If you know of a great place to get more awesome icons for applications, please post it in the comment area below.
