) is probably the best-of-breed program out there. I'm using it right now for professional video work.
The program already supports threads, and from an application program point-of-view that means that "it supports SMP." (SMP=Symmetric MultiProcessing... more than one CPU.)
The kernel, and only
the kernel, determines how and where the eligible threads may be dispatched, and on what processor(s). If an application makes multiple threads available, it creates the opportunity .. but never the guarantee .. that it may be dispatched on multiple CPUs.