-
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.
https://github.com/torvalds/linux/ (i can understand the code here once I know what it's for, I used this as a reference when I was implementing printf (https://elixir.bootlin.com/linux/latest/source/kernel/printk/printk.c), making a filesystem driver (https://elixir.bootlin.com/linux/latest/source/fs/isofs), etc)
https://github.com/id-Software/DOOM/tree/master/linuxdoom-1.10 (i absolutely love it)
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.