Back in 2008 I created an app called Proxima Controller. It’s a virtual MIDI controller that runs on Windows, OSX, and Linux.
I wanted an easy way to control external MIDI hardware (synthesizers, etc.) from my PC and there wasn’t an app that I liked available.
It started out as a Windows-only app. A few years later I ported it to Linux. And last year I ported it to OSX (but didn’t release it via the app store).
It’s been one of my more popular apps, with more than 70,000 downloads. I’m glad people have found it useful. It certainly made it easier for me to test sounds on my rackmount audio equipment without needing to shuffle full-sized MIDI keyboards around.
When I have time I’d also like to add an X-Y controller pad, something that can be used to transmit the same controller messages as the joystick on the Korg Wavestation and the Yamaha SY22/SY35/TG33.