Nerd Fonts
Iconic font aggregator, collection, & patcher. 3,600+ icons
... takes popular programming fonts and adds a bunch of Glyphs. There is also a font patcher available if your desired font isn't already patched. For more high-level information see the wiki. Includes an option to create Monospaced (fixed-pitch, fixed-width) or double-width (non-monospaced) glyphs.