FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
CKEditor - Real-time collaborative future-ready rich text editor
Glyphs - Make everything from dingbat webfonts to full-fledged text typefaces in the most Mac-like font...
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
FontCreator - This professional font editor allows you to create and edit TrueType and OpenType fonts.
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.