"Chung-chieh Shan and [Oleg Kiselyov] have submitted a paper [.pdf] on delimited contexts in operating systems and the zipper OS (which has not been formally published). Systems programmers do use contexts whether they are aware of that or not. The first version of UNIX on PDP-7 already implemented delimited continuations, in the form of co-routines between user programs and the shell. Being aware of delimited continuations may help systems programmers to better implement context switching, signal handling, etc., using the techniques developed in programming language research. It also leads to new insights, for example, that checkpointing a process and snapshotting a file system are essentially the same activity."