Scala Native is an optimizing ahead-of-time compiler and lightweight managed runtime for Scala, enabling compilation of Scala code to native executables. The repository implements the full toolchain: a Scala compiler plugin (nscplugin) that emits an intermediate representation (NIR), a linker and optimizer (tools) that perform reachability analysis, inlining, and code generation targeting LLVM, and a native runtime (nativelib) with multiple garbage collectors (immix, commix, Boehm), memory management (zones, unsafe pointers), and platform abstractions. It also provides extensive reimplementations of the Java standard library (javalib), POSIX and Windows bindings (posixlib, windowslib), and a JUnit test framework adapted for native execution. The project is highly modular, with over 3500 files spanning compiler internals, runtime C code, and library ports. It is actively maintained with frequent commits and a large test suite covering JDK compatibility, concurrency, and platform-specific behavior. Notable technical depth includes a custom NIR serialization format, graph-coloring for trait dispatch, polymorphic inline caching, and concurrent garbage collection algorithms.
Scalaz is a mature, purely functional programming library for Scala, providing a comprehensive set of type classes (Functor, Monad, Traverse, Foldable, etc.), monad transformers (OptionT, StateT, WriterT, etc.), effect types (IO, ST, RegionT), efficient immutable data structures (IList, Tree, FingerTree, Heap, Dequeue, etc.), and syntactic enrichment for all of the above. It is organized into modular sub-projects (core, effect, iteratee, scalacheck-binding) and supports cross-compilation to JVM, JavaScript, and Native platforms across Scala 2.13 and 3. The library is designed for production use and serves as both a practical toolkit and a reference implementation of category theory concepts in Scala. While primarily a library, it contains advanced research-level abstractions (free monads, cofree comonads, finger trees) that make it a valuable resource for functional programming education.