I didn’t know what Wabi was, but found the Wikipedia article useful
Win4Lin 9x was based on the somewhat similar SCO Merge and was a very fast way to run Windows 95/98 on Linux:
I used it for several years on Linux. Typing ‘win’ in your shell and having Windows 98 on X11 in a few seconds was magical. It was also faster and better intergrated than the first versions of VMWare.
Though I guess the merge kernel extension is a nightmare. Different times.