[idle_zealot]

The term the author is looking for is Freeware or Shareware.

In today's world the equivalent is FOSS. You don't really have ownership of software if you can't modify it, or pay someone else to. Not having source code is itself a sort of DRM.

[dpassens]

No, the author explicitly mentions that paid software would also meet those definitions, provided you only need to pay once.