itk.js combines Emscripten and ITK to enable high-performance spatial analysis in a JavaScript runtime environment.

The project provides tools to a) build C/C++ code to JavaScript (asm.js) and WebAssembly, b) bridge local filesystems, native JavaScript data structures, and traditional file formats, c) transfer data efficiently in and out of the Emscripten runtime, and d) asynchronously execute processing pipelines in a background thread. itk.js can be used to execute ITK, VTK or arbitrary C++ codes in the browser or on a workstation / server with Node.js.