MeCab is a Part-of-Speech and Morphological Analyzer for the Japanese language.
Originally written in C++, here I have used Emscripten and Binaryen to compile it to WebAssembly. This webpage acquires and executes a .wasm binary.
WebAssembly is an experimental low-level programming language for (very new) web browsers.
Chrome Canary requires you to enable Experimental WebAssembly in chrome://flags#enable-webassembly.
Firefox Nightly requires you to enable javascript.options.wasm in about:config.