Open Source
Disclaimer: These are open source projects that we found useful. Some aren’t being maintained, some have various bugs. We will try to keep them up to date, but we don’t claim ownership. If you like what we do, please consider donating to us.
midiChordAnalyzer

midiChordAnalyzer guesses chord names based on MIDI input, or from clicked notes on the keyboard display. VST 32bit, VST 64 bit and executable are available here.
AudioChordAnalyzer
AudioChordAnalyzer is a real time chord analyzer using audio as input.