Release Notes: The "--keep" (-k) option was added to not delete input files, in line with other tools such as xz, lzip, and bzip2. A decompression issue with certain invalid data in the 'pack' format was fixed. An incorrect overwrite when compiled with optimization was fixed. zgrep's handling of multi-digit context options was fixed. zmore now acts more like 'more'.
Release Notes: CRC16 header checksums according to RFC 1952 are now checked and decoded. A case of accidental interactive input file removal was eliminated. Decompression of mixed compressed and uncompressed streams now works. Double-compression is avoided better. Various other changes were made.
Release Notes: Many changes were made since the last announcement. Most notably, a security vulnerability potentially allowing arbitrary code execution, reported as CVE-2010-0001, was fixed. Many other minor bugs were fixed.