string_decoder.js (require('string_decoder')) from Node.js core
Copyright Joyent, Inc. and other Node contributors. See LICENCE file for details.
Version numbers match the versions found in Node core, e.g. 0.10.24 matches Node 0.10.24, likewise 0.11.10 matches Node 0.11.10. Prefer the stable version over the unstable.
The build/ directory contains a build script that will scrape the source from the joyent/node repo given a specific Node version.