Revolution is descended in spirit from Hypercard (HC). When Apple’s support for HC withered, Scott Raney developed Metacard (MC), a near clone. Metacard was then bought by Revolution (RR), based in Scotland. Metacard was two quite distinct things: an engine, and an IDE. When Metacard was sold, the MC IDE became public domain. It still exists, is volunteer maintained, and it can be used with the latest RR engine. Some on the RR user mailing list prefer the much simpler MC IDE to the RR IDE, at least for initial project development. Other IDEs are possible, and there is a third party (non-free) IDE called Galaxy.