QPACK is the compression mechanism used by HTTP/3 to compress HTTP headers. It
is in the process of being standardazed by the QUIC Working Group. The QPACK
Internet-Draft is has been stable for some time and we don't expect functional
changes to it before the final RFC is released.

ls-qpack is a full-featured, tested, and fast QPACK library. The QPACK encoder
produces excellent compression results based on an innovative mnemonic technique
(to be described in a future article). It boasts the fastest Huffman encoder and
decoder.

The library is production quality. It is used in OpenLiteSpeed, LiteSpeed Web
Server, and LiteSpeed Web ADC.