A programming language that has the semantics necessary to elegantly express a new kind of garbage collector. A rudimentary prototype of the collector, written in C++ with a terrible interface, appeared to confirm the idea.
At least, that was the initial goal. The more I investigate the design choices involved in programming languages, the more room for improvement I see.
This is the fifth bimonthly What Are You Working On? thread. Previous threads are here. So here's the question:
What are you working on?
Here are some guidelines: