Andrew Grove, Intel’s legendary co-founder and former CEO, passed away on Monday at 79, Intel said. He was one of the business world’s most revered leaders who helped to usher in today’s era of computing. He was a Time Person of the Year who was known for his famous mantra against corporate complacency, “Only the paranoid survive.” News of Grove’s cut deep in the technology industry, in which he was a source of inspiration.

Here’s a selection of what many high-profile leaders said about Grove following his death:

Apple CEO Tim Cook:

Kleiner Perkins Caufield & Byers partner John Doerr:

Marc Andreessen, Netscape co-founder and co-founder of Andreessen Horowitz:

Ben Horowitz, co-founder with Andreessen Horowitz:

Yuanqing Yang, chairman and CEO of Lenovo:

Intel CEO Brian Krzanich:

Microsoft CEO Satya Nadella:

Salesforce CEO Marc Benioff

Dell CEO Michael Dell:

VMware CEO Pat Gelsinger

Matthew Prince, CEO of business technology company Cloudflare: