How KZIP Compression Works:

KZIP is a specialized, freeware command-line file compression utility created by legendary game programmer Ken Silverman (famous for creating the Build engine behind Duke Nukem 3D).

Unlike general-purpose archivers that focus on speed, KZIP is explicitly engineered for maximum data density. It creates standard .zip files that are 10% to 20% smaller than traditional utilities, but it takes significantly longer to finish compressing. The Core Mechanism: Extreme DEFLATE Optimization

KZIP doesn’t introduce a new file format. Instead, it uses the standard, universally compatible DEFLATE compression algorithm. DEFLATE inherently relies on two layered lossless techniques:

ELI5: What is and how does a ZIP file work? : r/explainlikeimfive