The E language made light-weight promise pipelining accessible. This ought to be a crucial idea for the upcoming multi-core revolution, as it makes it possible to write code that's easily parallelized, has low-cost dependencies between communicating sub-processes, and sidesteps all the standard problems with managing locks and avoiding deadlock. The main ideas in E have been ported to a variety of other languages. E is part of a long (though somewhat obscure) line of object capability languages, which has some very important contributions to make in software robustness and security. E is just about 10 years old now.
