Web-based MKV player with subtitle support.
Try it out now: https://mkv-player.netlify.com/
This is a Javascript web-app to play .mkv files with embedded .ass or .ssa subtitles. Javascript is used to extract the fonts and subtitles before being rendered using a WebAssembly version of libass.
Especially useful for Chromebooks where there are no native video player with .ass or .ssa support available.