The Wasmer runtime crates

The philosophy of Wasmer is to be very modular by design. It's composed of a set of crates. We can group them as follows:

• api — The public Rust API exposes everything a user needs to use Wasmer programatically through the wasmer crate,
• cache — The traits and types to cache compiled WebAssembly modules,
• cli — The Wasmer CLI itself,
• compiler — The base for the compiler implementations, it defines the framework for the compilers and provides everything they need:
  • compiler-cranelift — A WebAssembly compiler based on the Cranelift compiler infrastructure,
  • compiler-llvm — A WebAssembly compiler based on the LLVM compiler infrastructure; recommended for runtime speed performance,
  • compiler-singlepass — A WebAssembly compiler based on our own compilation infrastructure; recommended for compilation-time speed performance.
• derive — A set of procedural macros used inside Wasmer,
• engine — The general abstraction for creating an engine, which is responsible of leading the compiling and running flow. Using the same compiler, the runtime performance will be approximately the same, however the way it stores and loads the executable code will differ:
  • engine-universal — stores the code in a custom file format, and loads it in memory,
• types — The basic structures to use WebAssembly,
• vm — The Wasmer VM runtime library, the low-level base of everything.