-
InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
If LGPL2.1 is acceptable, Nes_Snd_Emu would be an option to look at. (actually looks like that's a copy of Blargg's Nes_Snd_Emu, maybe modified; I didn't check).
NOTE:
The number of mentions on this list indicates mentions on common posts plus user suggested alternatives.
Hence, a higher number means a more popular project.