Bill Gates releases the original Microsoft source code that started it all!

As Microsoft celebrates its 50th anniversary, co-founder Bill Gates has released a significant piece of software history—the original source code that laid the foundation for the tech giant.

In a blog post on Gates Notes on April 2, Gates shared the code, calling it “the coolest code” he has ever written. “Making it to 50 years is an incredible achievement, and it wouldn’t have been possible without visionary leaders like Steve Ballmer, Satya Nadella, and the countless talented individuals who shaped Microsoft over the decades,” he wrote.

Reflecting on the company's origins, Gates recalled working with Paul Allen at Harvard’s computer lab, where they developed the first Microsoft product. Their journey began in 1975 when they saw the Popular Electronics magazine featuring the Altair 8800—a personal computer by MITs.

Excited by the potential, the duo contacted the Altair’s creators, claiming they had developed a version of the BASIC programming language for it—though, at the time, they hadn’t written a single line of code. “It was time to get to work,” Gates admitted. Over two months of intense programming, they created Altair BASIC, which became the first product of their startup, originally named Micro-Soft before the hyphen was dropped.

Gates’ blog post includes rare images from the company’s early days, offering a nostalgic glimpse into Microsoft’s rise from a college project to a global powerhouse.