Someone rediscoved Windows 98 HTA archives.

https://en.wikipedia.org/wiki/HTML_Application

The original Electron! Pity the versions of IE it was available for were still hell to debug in.

Back in those days you had to install the Office Scripting Debugger, I think that was the name, when browser debuggers were still extensions.

Before that it likely was Outlook Web Access.

https://en.wikipedia.org/wiki/Outlook_on_the_web

HTAs were equal parts great (for their time) and terrible (plus they stuck around until IE died): a bog-standard webpage, but IE-only and with local-user process execution powers. Also, the local persistence was...problematic.

Only similar in the vaguest sense.

Came here to comment the same.