Here is a proof of concept redis emscripten port I have made.
It hasn't required a lot of modifications to work, which mostly are commenting out clustering, persistence, lua, sentinel and other stuff.
Maybe the port has other limitations, I haven't done full testing,
but basic stuff works pretty well.
You can try it yourself, autocomplete commands work with the TAB key
(Modern browsers with asm.js support are required for speed).
about 700kb scripts will be downloaded