FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
Feather Icons - Simply beautiful open source icons
FontCreator - This professional font editor allows you to create and edit TrueType and OpenType fonts.
Icons8 - Free app for Mac & Windows already containing 39,800 icons. Allows to search and import icons…
Fony - Fony is an editor for bitmap (raster) fonts.
Streamline icons - The world’s largest icon pack library - 100k icons and illustrations.