https://github.com/thelounge/thelounge
It's a node based IRC client you can install on a server and then connect to with a web browser.
It essentially turns IRC into slack/irc cloud, it has inline images/video, URL prefetching, push notifications, themes and custom css, mobile support, and allows you to idle indefinitely persisting your connection to your favorite channels across numerous devices. You can even hook it into active directory if you wanted.