Javascript is increasingly being used not just for client-side programming and server-side programming with Node.js, but for the creation of traditional desktop applications. This is being facilitated by the creation of the Electron development platform, which is what Slack used to create their desktop application and what Brendan Eich used to create Brave.
http://www.wired.com/2016/05/javascript-conquered-web-now-taking-desktop/
