I don't think it's "fanboyism" to point out one of the most important contemporaries of the Python async/await system, which is also one of the leading platforms that enables that pattern in production today.

And yes, you can access a list of async operations (not "threads"; some of them are threads and some of them are multiplexed IO selectors/pollers--know the difference) running at any point in time: https://www.html5rocks.com/en/tutorials/developertools/async...

The asyncio tools in python enable something similar, but very few scripting language debug/tracing tools are as robust as those for JS; that's another area where other languages are often inspired (or aspiring).