[Cthulhu_]

Examples: Microsoft's current design language is called Fluent Design. Google's is called Material Design, and Apple's... idk, their old one was Aqua and their current one is referred to as Cupertino I believe?

Not sure if they even gave names to designs back then though, I believe it only became a thing during a design transition era some time ago (moving away from 'skeuomorphic' to 'flat design').

[qbasic_forever]

Windows 3.1, Windows 95, Windows 98, XP, etc. There wasn't a cohesive design language it was just referred by the OS name. You had garish colorschemes (remember hot dog stand?... yeah) and lots of silly things. Win32 programming back then was barely one step above pushing pixels on a canvas and it showed. VB and OLE, then COM started to standardize prebuilt components like dialogs and such that could be shared and used between apps but it was still a wild west of design. Into the 90s it got worse as Windows 98 gave more control over rendering to apps and we had things like Winamp skins that looked like a modern stereo, or a (thankfully) brief period where non-square windows with ovals, curves, and all kinds of junk were in vogue (track down an old copy of Bryce 3D if you want to see something really wild). It's an era of computing that's probably best left forgotten. :)