Link to 1st and 2nd order Ambisonic VST and Direct Show decoders along with a new Ambisonic Reverb VST plug-in.
A new and interesting spatial audio system based on a combination of technologies has recently been announced by Günther Theile and colleagues at Hauptmikrofon.de. It gets round the limitations of crosstalk cancelled binaural presentation by making use of Wavefield Synthesis Techniques. Details at the link below.
Ambisonic Bootlegs - an on-line resource for Ambisonic surround sound recordings. This includes details on how to play them on various systems (PC, MAC, Linux).