The Rise and Tragic Fall of Phil Katz, Father of the ZIP Format

PKZIP’s Birth and Impact

On Valentine’s Day 1989, programmer Phil Katz released PKZIP, a simple compression tool that would, over the next three decades, become a foundational internet standard, allowing users to open ZIP files directly in Windows.

ARC War and Patent Dispute

Before PKZIP, the ARC format from System Enhancement Associates (SEA) dominated BBS compression. Katz’s early PKARC borrowed SEA’s technology, prompting SEA to sue. The resulting "ARC war" ended with Katz rewriting the algorithm and launching PKZIP.

Katz made the bold decision to publish the ZIP specification (APPNOTE.TXT) publicly, enabling anyone to implement ZIP support for free. This open approach removed patent barriers, leading to rapid adoption across operating systems, including Microsoft’s integration of ZIP support into Windows.

Downward Spiral: From Luxury to Motels

Later in life, Katz’s behavior grew erratic; neighbors complained of foul odors and infestations in his upscale apartment. Police raids revealed piles of trash and rotting food, prompting Katz to retreat to motels between Milwaukee and Chicago, severing family ties.

He accumulated countless DUI arrests and, over years of heavy drinking, his health deteriorated.

Lonely End

On April 14, 2000, Katz was found dead in a Milwaukee County motel room at age 37. Autopsy reports showed pancreatic bleeding and a cirrhotic, enlarged liver—classic signs of chronic alcohol poisoning. He was discovered clutching an empty bottle, with additional bottles scattered nearby.

Dave Plummer later reflected, "I never saw Phil before he fell into darkness. I wonder what we would have talked about if we had met."

The Man Behind the Code

Katz was described as a reclusive "absent lone wolf" by his 20‑person staff, disinterested in public appearances yet unafraid of extracting profit. Friends recalled that when he drank, he became talkative, jovial, and worked longer hours, a pattern that ultimately consumed him.

Some liken his trajectory to "Howard Hughes syndrome," where brilliance and self‑destruction coexist.

Our Debt to Him

Today, when users right‑click "Send to → Compressed (zipped) folder" in Windows, they rely on code Katz wrote over three decades ago. By releasing the ZIP format openly, he enabled a universal standard, even though he received little financial reward and died in poverty and isolation.

The story underscores that technological progress can be ruthless—it can create enduring formats while failing to safeguard the souls behind them.