jit - Enable just-in-time compilation for improved performance. May prevent use of some PaX memory protection features in Gentoo Hardened.
low-memory - Build using PyPy with the engine configured towards low memory footprint. This makes it possible to build PyPy using ~3.5G of RAM on amd64 and ~half of that on x86, at the cost of lengthened build time.
ncurses - Add ncurses support (console display library)