binaryen : Compiler and toolchain infrastructure library for WebAssembly ( https://github.com/WebAssembly/binaryen )
emscripten : Emscripten is a complete compiler toolchain to WebAssembly, using LLVM ( https://emscripten.org )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a darthgandalf-overlay
For Paludis use this rsync : rsync://gentoo.zugaina.org/darthgandalf-overlay-portage
If you have a problem : ycarus(-at-)zugaina.org