dadhi/FastExpressionCompiler

Compiles expression trees 10-40x faster than standard `.Compile()` by leveraging IL generation and avoiding the sandbox overhead of DynamicMethod, while producing delegates with comparable or superior runtime performance. Provides LightExpression—a stripped-down alternative to System.Linq.Expressions that reduces memory footprint for scenarios prioritizing compilation speed over full expression flexibility. Widely adopted by DI containers (DryIoc, Lamar, StructureMap), ORMs (LINQ2DB, Marten), serializers (Apex.Serialization, Mapster), and message brokers (Rebus, NServiceBus).

1,349 stars. Actively maintained with 16 commits in the last 30 days.