Birdfont is a free font editor which lets you create vector graphics and export TTF, EOT and SVG fonts.
Transform your handwriting or calligraphy into a font! Creating your own font has never been easier. With your own font you can create genuine personal designs and calligraphic artwork. Free and pro version.
FontStruct is a free, font-building tool sponsored by FontShop. With FontStruct you can easily create fonts using geometrical shapes. Once you’re done building, FontStruct generates TrueType fonts, ready to download and use in any application.
Glyphr Studio is a free, web based font designer. Font design has a high barrier of entry. Professional font design programs are very complex, and/or quite expensive. Glyphr Studio is streamlined and made for font design hobbyists… and it’s free!
Type 3.2 is an “easier-to-use, yet comprehensive font editor”. For artists, techies, or maybe just hobbyists wanting to make fonts. Try the free demo for Windows and Mac – full professional license also available.
FontForge is an outline font creator, editor and converter. For PostScript, TrueType, OpenType, svg and bitmap fonts. If you want to learn all about font design, they also offer a free Design with FontForge PDF!