LightweightCodeGen

This is Microsoft-speak for a (more recent) part of their Reflection.Emit CLR library that is specialized around generating:

• Functions rather than objects
• in a simple manner (no app domains, assemblies, or modules)
• that can be garbage collected

That last bit is the most important; it means that we can actually adopt CompileOnEval on CommonLarceny if we switch to using LightweightCodeGen.