Hey HN, the author here. This is the second iteration of what I thought out to be a platform (then named CodeSheets) for code snippet repos with a built-in code runner. Instead of building my own code repo platform, I am utilizing GitHub, GitLab and BitBucket and have added runners on each of them through a browser extension. In addition to browsing and storing snippets on GitHub, now you can even execute them without leaving your browser! You can run a Hello World program in every language[1] right from your browser without installing anything! (Okay, not every yet, but you get the point.)
Due to the extensible architecture of the code, it is easy to add support for any website which has standalone code snippets. With the optional permissions, adding new websites (read host permissions) doesn't block extension updates. I have added support for Go by Example[2] and Tutorials Point[3] with just a few lines of code.
Even though it has been actually public for more than a year now, only recently I became confident in advertising it to a broader audience. Currently, it has more than 1000 weekly active users across Chrome and Firefox.
For more info, check out the FAQ[4]. Any feedback is welcome.
PS: I am currently a graduate student at ASU, looking for a Summer internship.