Zstd

new : long range mode, using --long command, by Stella Lau (stellamplau)
new : ability to generate and decode magicless frames (591)
changed : maximum nb of threads reduced to 200, to avoid address space exhaustion in 32-bits mode
fix : multi-threading compression works with custom allocators
fix : ZSTD_sizeof_CStream() was over-evaluating memory usage
fix : a rare compression bug when compression generates very large distances and bunch of other conditions (only possible at --ultra -22)
fix : 32-bits build can now decode large offsets (levels 21+)
cli : added LZ4 frame support by default, by Felix Handte (felixhandte)
cli : improved --list output
cli : new : can split input file for dictionary training, using command -B
cli : new : clean operation artefact on Ctrl-C interruption
cli : fix : do not change /dev/null permissions when using command -t with root access, reported by mike155 (851)
cli : fix : write file size in header in multiple-files mode
api : added macro ZSTD_COMPRESSBOUND() for static allocation
api : experimental : new advanced decompression API
api : fix : sizeof_CCtx() used to over-estimate
build: fix : no-multithread variant compiles without pool.c dependency, reported by Mitchell Blank Jr (mitchblank) (819)
build: better compatibility with reproducible builds, by Bernhard M. Wiedemann (bmwiedemann) (818)
example : added streaming_memory_usage
license : changed /examples license to BSD + GPLv2
license : fix a few header files to reflect new license (825)

New license : BSD + GPLv2
perf: substantially decreased memory usage in Multi-threading mode, thanks to reports by Tino Reichardt (mcmilk)
perf: Multi-threading supports up to 256 threads. Cap at 256 when more are requested (760)
cli : improved and fixed --list command, by ib (772)
cli : command -vV to list supported formats, by ib (771)
build : fixed binary variants, reported by svenha (788)
build : fix Visual compilation for non x86/x64 targets, reported by Greg Slazinski (GregSlazinski) (718)
API exp : breaking change : ZSTD_getframeHeader() provides more information
API exp : breaking change : pinned down values of error codes
doc : fixed huffman example, by Ulrich Kunitz (ulikunitz)
new : contrib/adaptive-compression, I/O driven compression strength, by Paul Cruz (paulcruz74)
new : contrib/long_distance_matching, statistics by Stella Lau (stellamplau)
updated : contrib/linux-kernel, by Nick Terrell (terrelln)

cli : new : `--list` command, by Paul Cruz
cli : changed : xz/lzma support enabled by default
cli : changed : `-t *` continue processing list after a decompression error
API : added : ZSTD_versionString()
API : promoted to stable status : ZSTD_getFrameContentSize(), by Sean Purcell
API exp : new advanced API : ZSTD_compress_generic(), ZSTD_CCtx_setParameter()
API exp : new : API for static or external allocation : ZSTD_initStatic?Ctx()
API exp : added : ZSTD_decompressBegin_usingDDict(), requested by Guy Riddle (700)
API exp : clarified memory estimation / measurement functions.
API exp : changed : strongest strategy renamed ZSTD_btultra, fastest strategy ZSTD_fast set to 1
tools : decodecorpus can generate random dictionary-compressed samples, by Paul Cruz
new : contrib/seekable_format, demo and API, by Sean Purcell
changed : contrib/linux-kernel, updated version and license, by Nick Terrell

cli : changed : Multithreading enabled by default (use target zstd-nomt or HAVE_THREAD=0 to disable)
cli : new : command -T0 means "detect and use nb of cores", by Sean Purcell
cli : new : zstdmt symlink hardwired to `zstd -T0`
cli : new : command --threads= (671)
cli : changed : cover dictionary builder by default, for improved quality, by Nick Terrell
cli : new : commands --train-cover and --train-legacy, to select dictionary algorithm and parameters
cli : experimental targets `zstd4` and `xzstd4`, with support for lz4 format, by Sean Purcell
cli : fix : does not output compressed data on console
cli : fix : ignore symbolic links unless --force specified,
API : breaking change : ZSTD_createCDict_advanced(), only use compressionParameters as argument
API : added : prototypes ZSTD_*_usingCDict_advanced(), for direct control over frameParameters.
API : improved: ZSTDMT_compressCCtx() reduced memory usage
API : fix : ZSTDMT_compressCCtx() now provides srcSize in header (634)
API : fix : src size stored in frame header is controlled at end of frame
API : fix : enforced consistent rules for pledgedSrcSize==0 (641)
API : fix : error code "GENERIC" replaced by "dstSizeTooSmall" when appropriate
build: improved cmake script, by Majlen
build: enabled Multi-threading support for *BSD, by Baptiste Daroussin
tools: updated Paramgrill. Command -O provides best parameters for sample and speed target.
new : contrib/linux-kernel version, by Nick Terrell

cli : new : can compress in *.gz format, using --format=gzip command, by Przemyslaw Skibinski
cli : new : advanced benchmark command --priority=rt
cli : fix : write on sparse-enabled file systems in 32-bits mode, by ds77
cli : fix : --rm remains silent when input is stdin
cli : experimental : xzstd, with support for xz/lzma decoding, by Przemyslaw Skibinski
speed : improved decompression speed in streaming mode for single shot scenarios (+5%)
memory: DDict (decompression dictionary) memory usage down from 150 KB to 20 KB
arch: 32-bits variant able to generate and decode very long matches (>32 MB), by Sean Purcell
API : new : ZSTD_findFrameCompressedSize(), ZSTD_getFrameContentSize(), ZSTD_findDecompressedSize()
API : changed : dropped support of legacy versions <= v0.3 (can be changed by modifying ZSTD_LEGACY_SUPPORT value)
build : new: meson build system in contrib/meson, by Dima Krasner
build : improved cmake script, by Majlen
build : added -Wformat-security flag, as recommended by Padraig Brady
doc : new : educational decoder, by Sean Purcell

cli : zstd can decompress .gz files (can be disabled with `make zstd-nogz` or `make HAVE_ZLIB=0`)
cli : new : experimental target `make zstdmt`, with multi-threading support
cli : new : improved dictionary builder "cover" (experimental), by Nick Terrell, based on prior work by Giuseppe Ottaviano.
cli : new : advanced commands for detailed parameters, by Przemyslaw Skibinski
cli : fix zstdless on Mac OS-X, by Andrew Janke
cli : fix 232 "compress non-files"
dictBuilder : improved dictionary generation quality, thanks to Nick Terrell
API : new : lib/compress/ZSTDMT_compress.h multithreading API (experimental)
API : new : ZSTD_create?Dict_byReference(), requested by Bartosz Taudul
API : new : ZDICT_finalizeDictionary()
API : fix : ZSTD_initCStream_usingCDict() properly writes dictID into frame header, by Gregory Szorc (511)
API : fix : all symbols properly exposed in libzstd, by Nick Terrell
build : support for Solaris target, by Przemyslaw Skibinski
doc : clarified specification, by Sean Purcell