One of the authors here. The neat thing about this set up is that these streaming examples are executing against a real stream processor in the browser.
The interactive examples were built using [Onyx](<a href="https://github.com/onyx-platform/onyx" rel="nofollow">https://github.com/onyx-platform/onyx</a>) and it's cross-compiled JavaScript sibling, [onyx-local-rt](<a href="https://github.com/onyx-platform/onyx-local-rt" rel="nofollow">https://github.com/onyx-platform/onyx-local-rt</a>).