Per the homepage:
"New Snem was started a while ago, and has had _very_ slow progress. It's supposed to have cycle-accurate CPU and better PPU emulation, though it has mostly failed (so far). The PPU emulation is much better, supporting colour add/sub (with a couple of bugs in a few games), windowing, high res (ish). New SPC700 + DSP emulation has been added, and works with most games, though timing is a little off (which is probably breaking SD3). Compatibility is miles better than old SNEm. The speed isn't though - while old SNEm was written on a P2-350, and hence is usable on such a machine, New Snem needs about 1ghz".
Get it here: