NexusFont - Choose and manage your fonts with Nexus Font.
Microsoft Font Validator - A tool that evaluates how closely a TrueType or OpenType font adheres to the current font format...
Font Manager - Simple font management for GTK+ desktop environments
FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
FontExpert - FontExpert - Font Manager for Windows, Photo Manager for Digital Photography.
Apple Font Tool Suite - A suite of tools for working with font files.