http://libcaca.zoy.org/wiki/CPUShare

As a side note, as long as this project will remain active, the seccomp API will be fully maintained. The only reason the seccomp API was being obsoleted by KVM in the CPUShare roadmap is that nobody used it for their own project yet, but this changed now.

The roadmap still includes the KVM support but it won't obsolete seccomp anymore unless all seccomp projects prefers to switch to KVM for whatever reason later. Seccomp still provides substantial advantages to the buyers (most important is the low overhead to distribute the executables) even if it's a lot harder to program with.