This was AMI's notorious WinBIOS. Pretty much anything with an AMI BIOS from the middle of the 1990s had it. I have an MG TK8498F (Baby AT ISA + VLB board with UM8498F chipset) with it, but this board is more obscure than most. You'll also find it on many MSI boards etc. etc. etc.

I had a Shuttle Hot 443 motherboard (Baby AT ISA + PCI + Integrated I/O (HDD, FDD, RS232, LPT)) that had that BIOS. It looked like Windows 3.0 on steroids and mouse friendly (either a bus mouse, serial mouse, or PS/2 mouse are supported). There were a few eMachines in the late 1990's (Slot 1-Socket 370) that had that as well.

The only way you can tell is by the BIOS string at the POST screen (memory count), I believe, but, I could be wrong.

I'll try to answer it myself. According to Wiki, the AMI WinBIOS was a 1994 update to AMIBIOS. So it's likely that the BIOS chip should at the very least have 1994 sticker (unless an older one was reprogrammed at some point).

My 486 build has it, and if you check out the thread in my signature, you'll see that it has a 1993 date on the chip.

There's some 1993 WinBIOSes as well..

Certainly not a "decent" VLB board... but PCChips M919 comes with WinBios too.

AMI didn't use version numbers in a traditional sense. Their 80s and 90s BIOS were identified by the core release date (not to be confused with the OEM's release date). The first WinBIOS core appears to have been 12/15/93. While the WinBIOS was released in late 1993, almost all the boards date from 1994 and newer. The latest boards I've seen with the WinBIOS are SuperMicro boards from 1998-99.