[rmunn]

https://github.com/CodyReichert/awesome-cl lists some concurrency packages, such as https://github.com/sionescu/bordeaux-threads and https://github.com/sharplispers/lparallel, as being "so widespread and solid that they became community standards. You can't be wrong with them." I don't know enough to know whether or not they're right about those being widespread, but if that list is wrong then I'm sure someone will chime in to say so.

So while the official standard may not have concurrency, that does not mean that there isn't a de facto community standard way to do it.