Of course once the makefile is generated, there is no need to use cmake (as long as the project is not modified), but you cannot share a makefile generated by cmake, not even redistribute it. You cannot even re/locate it on your hard drive.

The difference is that autotools generates source distributions that do not need autotools to build, while a cmake project always requires cmake when building.

Oh, I wasn't aware it wasn't distributable, my bad.

Can we give everyone exactly the same tarball of a project and just have it unpack and build on their platform?

I think so, if you pre-generate the build files for every platform and distribute them all in the tarball.

Haha