We started as just an editor and a console -- I initially modeled it after the Dr Scheme REPL (now Racket) -- but our users wanted more. Kids who learned to code using our repl wanted to use it to build and publish apps so we evolved the product towards becoming more of an IDE while trying to keep the simplicity.

Check out our community as well, lots of hackers, especially young ones, sharing and collaborating on code: https://repl.it/talk