Opus, a low-delay audio codec optimized for both voice and general-purpose audio, has been approved by the IETF. Originally developed by Xiph, Opus is a merger of Skype’s SILK’s and Xiph’s CELT codecs.
Xiph, which was originally made Opus/CELT for the low-latency audio, has become competitive in the general purpose audio codecs area.
As it turns out, with the recent builds of Firefox, guys at Mozilla have adopted Opus natively as it can be enabled be settng media.opus.enabled to true in Aurora or Nightly build’s about:config.
Although Opus is still in draft state, expect to see the very first 1.0 release within 6-8 weeks