MetricsMachine is a commercial kerning app for Mac OS X developed by Tal Leming (TypeSupply).
MetricsMachine is streamlined for a professional workflow: you create groups of similarly shaped glyphs, then you create lists of pairs that you want to proof, then you proof those pairs one at a time until you are finished, then you export your kerning to an OpenType ready feature file.
![](https://typography.guru/uploads/monthly_2015_01/metricsMachineMainWindow.png.eed6609b963b8490db155321c2d74bae.png)