FreeBSDKit
A framework for building secure, capability-aware applications on FreeBSD.
<https://github.com/vIsNotUNIX/FreeBSDKit/>
"FreeBSDKit provides idiomatic Swift, C and C++ interfaces to FreeBSD's unique system features including Capsicum sandboxing, jails, process descriptors, kqueue-based signal handling, and inter-process communication with descriptor passing. The framework embraces move-only semantics (~Copyable) to model resource ownership explicitly in the type system."
– Kory Heard