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 Viewer - Font Viewer is an application which does exactly that - it views fonts!
FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
Font Manager - Simple font management for GTK+ desktop environments
Apple Font Tool Suite - A suite of tools for working with font files.