Intel i432 had some of that (capabilities, garbage collection, multitasking, etc) but was crippled by a variety of problems—perhaps most of all that it was quit

Intel i432 had some of that (capabilities, garbage collection, multitasking, etc) but was crippled by a variety of problems—perhaps most of all that it was quite slow and expensive. It was originally intended to run a Smalltalk-like language, the name of which escapes me at the moment, but got retrofitted to run Ada. Unfortunately the Ada compiler for the i432 was awful, in addition to the slow hardware. It was a pretty fascinating idea though.