These kinds of things are best handled as an integrated component of the operating system, rather than a hacky third party add on, and are likely more viable now that we have so much more available CPU time, on multiple cores so it doesn't even impact latency, and better compression algorithms.
Also note that Ram Doubler, per the Ambrosia Software description, didn't just do compression, it also re-used free RAM that other applications had allocated to them while they weren't running, depending on the cooperative multitasking nature of the operating system to avoid conflicts. Before yielding, it would either compress or swap out that "borrowed" RAM.
A properly virtual memory system and cooperative multitasking make these techniques not particularly useful, while improvements in technology since have made compressed RAM more useful.
I wonder when airplanes are going to be new again, or books, or cars. Maybe you mean everything related to computers? I am not sure of even that though...
Concorde was a good try. It failed for political and sociological reasons, but hypersonic airplanes were set to revolutionize air travel until it became politically unpopular to support. We're facing down a generation designed around space-based air travel, though, so it could happen again.
