VBScript and HTA files (HTML Applications) come to mind. HTAs were actually an interesting direction, once used them to ship a simple application (a very visual FTP upload). It was unsandboxed HTML and JS that could access all the ActiveX APIs. A bit like Electron now.
Can't image there not being a few niches out there that heavily rely (or relied) on HTAs
That's nice. I once wrote a clone of Active Directory Users & Computers (dsa.msc) as a HTA, as I was working on a contract where I was expected to design stuff for the AD, but they wouldn't let me install the AD tools...
If all you have is Notepad, and you know how to write HTAs, the world is your oyster (or something).
I must say, supporting HTA can't be that big of a task, assuming the majority of those do not rely on any ActiveX controls. I guess MS could also probably write some replacements for the most popular ActiveX controls, and license them to their customers.
Can't image there not being a few niches out there that heavily rely (or relied) on HTAs