He received a bachelor's degree in computer science from the University of Wisconsin at Madison.
His first foray into the compression world started in the mid-1980s with a faster version of the popular ARC program, which he called PkArc. PkArc's speed quickly made it popular, much to the chagrin of the ARC authors, SEA. They sued and he was forced to change the program. However it appears the suit was not very specific, because he quickly released PkPac, which was similar in all but name.
Katz soon replaced PkPac with the new and completely re-written PKZIP. In addition to being much faster and compressing better than ARC, Katz kept the ZIP file format open. As a result, the PKZIP file format soon became the standard for file compression across all platforms. Katz released the DOS version of PKZIP as shareware, and it made Katz one of the most successful shareware authors of all time.
Katz died on April 14, 2000 from complications related to chronic alcoholism. He was 37 years old.