Programs written in languages like C/C++ can be ported to the web so they run with near-native performance with WebAssembly.
http://www.afterdawn.com/news/article.cfm/2017/03/08/webassembly-firefox-is-first-major-browser-to-support-game-changer
https://liliputing.com/2017/03/google-releases-chrome-57-webassembly.html
http://www.afterdawn.com/news/article.cfm/2017/03/08/webassembly-firefox-is-first-major-browser-to-support-game-changer
https://liliputing.com/2017/03/google-releases-chrome-57-webassembly.html