The Wasmer WebAssembly runtime provides various features for users and developers:

• Backends: Wasmer supports multiple compiler backends: Singlepass, Cranelift and LLVM. Each of these have different tradeoffs of compilation speed vs runtime speed.

• Caching: compiled WebAssembly modules can be reused so subsequent runs of a Wasm file will have very little start up time

• Metering: computation time and other resources can be monitored and limits set to control how the Wasm code runs. This is also known as "gas metering"

• WebAssembly Features:

  • Multi-value return: return multiple values from functions making data transfer between host and guest simpler

  • SIMD: Single Instruction, Multiple data: do heavy number crunching more quickly and/or with lower power usage

• ABIs: it allows to run different types of programs compiled to WebAssembly, with ABIs such as:

  • Emscripten

  • WASI

Support of features by Backend

Support by Operating System

• poll_fd is not fully implemented for Windows yet

Language integration

TODO: define a set of features that are relevant and mark them here

Current ideas:

• Callbacks

• Metering

• Caching

TODO: expand this table, it's focused on new features that we haven't implemented yet and doesn't list all language integrations