Freebies.ByPeople | Comercial use freebies for designers and developers
35 of the Best Icon Sets for Web Designers
50+ Free tools and resources to create awesome user interfaces (Part 2) - DEV
Flat Location Marker Icon - FlatIcons
System UIcons
1000+ free vector icons - Unicons - Iconscout
Material Icons Index
Free vectors icons for download and Icon font | Flaticon
Font Awesome, the iconic font designed for Bootstrap
The Big List of Flat Icons & Icon Fonts | CSS-Tricks
Climacons ≡ Climatically Categorised Pictographs
Elusive icons, an icons font designed for use with Bootstrap
Ajaxload - Ajax loading gif generator
Flat, simple icons for interface design — Owltastic — writing about web design by Meagan Fisher
Freebies: Twitter Icons for Your Blog | designrfix.com
Icon Theme Specification
Icon Naming Specification