FontForge is a free and open source font editor which supports many common font formats like all planes of UNICODE/ISO-10646. Developed primarily by George Williams until 2012, FontForge is free software and is distributed under a mix of the GNU General Public License Version 3 and the 3-clause BSD license. It is available for operating systems including Linux, Windows and macOS and is localized into 12 languages.
FontForge supports a wide variety of font formats. Supported font formats include: TrueType (TTF), TrueType Collection (TTC), OpenType (OTF), PostScript Type 1, TeX Bitmap Fonts, X11 OTB bitmap (only sfnt), Glyph Bitmap Distribution Format (BDF), FON (Windows), FNT (Windows), and Web Open Font Format (WOFF). FontForge also imports and exports fonts to and from the Scalable Vector Graphics (SVG) format and the Unified Font Object (UFO) format.
In addition, FontForge has a online book (Click here) about how to design new typefaces with FontForge, including much necessary and fundamental knowledge to create new fonts. Maybe that will be helpful.
Birdfont is a free font editor which lets you create vector graphics and export TTF, OTF, EOT and SVG fonts.
Glyphr Studio (Version 1), 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!
Additionally, Glyphr Studio has both web and desktop applications. You can visit (Click here) to try it out.
- Updates: 10/05/2019 Added more details in FontForge section