-
Roslyn
The Roslyn .NET compiler provides C# and Visual Basic languages with rich code analysis APIs.
-
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.
I hate to be that guy, but this has been an option since before Core 3.1: https://github.com/dotnet/roslyn/pull/30479, only a couple months after the release of C# 8.
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.