GeoBats is on – and it’s worth running a search for “icon” there to see some of the other stuff they have for free. GeoBats is an icon font of the world’s countries. StateFace has all 50 U.S states as an icon font. Pictonic also offers a hosted icon service and offers unique pricing ($0.59 per icon).

v2 is paid with the complete set at $25 or individual icons as low as $0.50. This works via OpenType, a typography feature of modern browsers. Symbolset is unique in that they turn words into icons for you. This allows for very small (quick loading) font files and a nice UI for updating your current sets. In additional to the sets, they also offer Pictos Server, a service which allows you to build your own font set from its library of icons and will host/serve it to you. Pictos is the icon font that really popularized this whole idea. I’m going to attempt to round them all up here and keep this updated (this post has already been updated several times).

But which do you choose? There are loads of different sets out there. Other than the fact that they have to be single color, they are superior to using images as icons in every way.

Marvel flat icon library