At my first job out of college in 2008 we wrote JS for a desktop app on top of Mozilla's xulrunner platform. At the time I hadn't heard of using JS outside the browser and Node was still a few years off. It was a great experience but Xulrunner got killed by Mozilla and the company had to rewrite in C#.
Just an example of (sort of) non-proprietary, non-browser JS.
But I used a few servers that allowed for JS scripting way before Node.
I guess, most of them were proprietary, so it never caught on until Node.