PKZIP

PKZIP is a file compression utility developed by PKWARE, originally created by Phil Katz for DOS and first released in 1989. It introduced the ZIP archive format, a widely used container for compressing and distributing files. The ZIP format and PKZIP became a de facto standard in personal computing, influencing many later archivers and utilities.

PKZIP was developed by PKWARE, Inc., after Katz's early work; its popularity grew as it provided reliable cross-platform support and a simple command-line interface in its early versions. Over time, PKZIP added support for multiple compression methods supported by ZIP archives, with the Deflate method becoming the most widely used. The ZIP format is widely implemented by many other tools, and the format description has been publicly documented to facilitate interoperability.

Key features include creating, extracting, and managing ZIP archives, with options for batch processing, self-extracting archives, and file integrity checks. Password protection via ZipCrypto was offered in earlier versions, with stronger encryption options, such as AES, added in later releases. PKZIP has been delivered for multiple platforms, including Windows and UNIX-like systems, and is complemented by a range of companion products and development libraries.

Impact and status: The ZIP format remains a dominant archive format for software distribution and data backup. PKWARE continues to maintain PKZIP alongside other data-compression tools, while numerous open and proprietary implementations support ZIP archives. The format's openness, combined with widespread tool support, has contributed to its enduring relevance in computing.