CPC (Continuation Passing C) is a programming language designed for writing concurrent systems. The CPC programmer manipulates very lightweight threads, choosing whether they should be cooperatively or preemptively scheduled at any given point; the CPC program is then processed by the CPC translator, which produces highly efficient event-loop code. This approach gives the best both worlds: the relative convenience of programming with threads, and the low memory usage of event-loop code. The semantics of CPC is defined as a source-to-source translation from CPC into plain C using a technique known as conversion into Continuation Passing Style. The current implementation of CPC has been used to write Hekate, a BitTorrent seeder designed to handle millions of simultaneous torrents and tens of thousands of simultaneously connected peers.
Shannon is a general purpose stream-oriented programming language; it is concise and yet feature rich. Streams, FIFOs, and Unix shell-style pipes are first-class concepts in the language. You can connect functions and FIFOs within your program similar to the way you connect processes with pipes in the Unix shell. These constructs in Shannon, however, are highly efficient as no true multitasking is involved, and at the same time they allow you to write more concise and readable code for chained data processing. State is a special type of function that returns a reference to its own local data and any nested functions it may have. In effect, states implement classes in terms of OOP, and yet classes per se aren't part of the language. A special type of modules marked as "persistent" is an effective replacement for databases and SQL. This allows you to access persistent shared data using native Shannon constructs, eliminating the need for an extra query language. Intuitive and minimalist syntax and semantics are used. Particularly, "minimalist semantics" means less things to remember and more possibilities. Shannon is statically-typed, although it provides dynamic typing facilities as well.