Kyle Hanson, Mon 2012-12-24 @ 15:49:44-0600:

Has anyone gotten this to work on Windows either native or on cygwin? Is there an alternative?

It may work on Cygwin, but I know for sure that it wouldn't run natively on Windows, as part of hsenv's functionality involves generating and executing bash scripts. If you've tried it with Cygwin and it didn't work, maybe give some more detail about the problems you're seeing. I am unable to try it out myself as I don't have any Windows machines, but others might be able to offer some insight.