This proposal from the High Performance Working Group entails the use of a FIX Trading Community designed Simple Binary Encoding (SBE) to produce fast and compact encodings of FIX messages. SBE provides different characteristics than other binary encodings. It is optimized for low latency.
This new FIX binary encoding complements the existing only binary encoding developed in 2005 (FAST) which had a focus on reducing bandwidth utilization for market data. In addition, the encoding is also defined and controlled within the FIX Trading Community, in contrast to the binary encodings proposals to encode FIX with Google Protocol Buffers and ASN.1.
Issues for corrections and proposed enhancements may be entered for future versions within the SBE GitHub project: https://github.com/FIXTradingCommunity/fix-simple-binary-encoding
The proposed technical standard for Simple Binary Encoding of FIX is following the technical standards review process described in the document found here.