I think it would be great if the website could be open up for external collaboration as an open source project.
I second this. Moreover, it might be good if projects such as this one started working towards open standards for this sort of thing (submitting and evaluating coding solutions). There are so many platforms (learning and education sites, competitive coding sites and so-called online judges, etc.) sharing similar functionality that it seems like this is bound to happen to some extent at some point - why not sooner rather than later?
We're working on it and in progress. We will enable you to contribute with Repl.it and in Repl.it, we will enable you to commit adding languages support to the website.
Other Open source projects like Facebook Jest and React uses Repl.it to reproduce bugs. we need your help to expand and spread the word.
Just an additional suggestion, being able to contribute integrations at the least would be cool.
@Braunson Yager: Can you explain more?