I used to use Babun at work. Essentially a nice bundle of a bunch of nice stuff for Cygwin.
It had this package manager but if you updated Cygwin itself then it would break everything. I had to get the Cygwin.dll file from a coworker because the install process downloaded it but I didn't want to reinstall lmao. I remember it being a pain because so many IT things were blocking us trying to share a dll file.
Had ipv6 stable with tunnels for years. Even the 1st provider offering ipv6 was using tunnels. All was well, until we needed to switch to SLAAC over pppoe. With creative source based routing, as I didn't want to sacrifice my tunnels before it was stable, I never could get it to work.
Years later, new provider, same technique, same ipv6 tunnels as main ipv6 option, I just gave up, SLAAC proved to unstable/unreliable in my setup. (Probably my doing, but I just can't get that route to reliably recover after a pppoe reset)
I still wish I could virtualize OS/2 in kvm... good old days of warp 3 and 4.0. Very stable for a BBS, with a Linux networked server next to it. (In '95)