I use a range of tools to facilitate various aspects of font engineering work, many of which I have developed myself. As far as possible, I make these tools available to anyone as open source.
An OpenType debugger which allows you step through the layout rules of a font and see what effect each one has.
An extensible layout language for font engineering; a replacement for the Adobe feature language.
A system for testing font shaping. I'm convinced that a rigorous testing framework provides the best way to ensure that fonts are reliable and correct when navigating complex and interwoven shaping behaviour.
A mixed bag of useful scripts and utilities.
A typesetting engine with a special focus on global scripts.
A Glyphs font editor plugin for collaborative development. Get it through the Glyphs Plugin Manager
An implementation of OpenType for Rust.