K (http://kx.com http://kx.com) seems to be, but unfortunately it's closed-source and quite expensive. From my (limited) experience with it, it's quite fast, e

K (http://kx.com http://kx.com) seems to be, but unfortunately it's closed-source and quite expensive. From my (limited) experience with it, it's quite fast, especially for an interpreted language. Its primitives are extremely cache-friendly and data-parallel, which helps performance immensely. Its design also cuts away layers and layers of typical boilerplate.