For those whose muscle memory is all confused now there's OpenDoas: https://github.com/Duncaen/OpenDoas
OpenDOAS has actually had the OpenBSD-specific code removed (https://github.com/Duncaen/OpenDoas/commit/74449f015ff7a7230...), and replaces some of the doas mechanisms that rely upon OpenBSD to work with sudo-like flag files and suchlike.
There are, moreover, 2 ports of doas to other systems. OpenDOAS is one. Jesse Smith's https://github.com/slicer69/doas is the other. The latter retains the OpenBSD-specific code, and is the more portable of the two at the expense of only doing everything that the tool is capable of when actually built on OpenBSD.