On August 25, 1991, Linus Torvalds made an announcement about a project he was working on. He wrote on the Minix mailing list that he was working on a free operating system for 386/486 AT clones, which he stated was just a hobby and wouldn't be big and professional like GNU.

It’s been 25 years since that announcement, and today, Linux is a dominating presence in the IT world. Linux powers a huge chunk of the Internet, as well as data centers, mission-critical operations like stock exchanges, supercomputers, mobile phones (Android), consumer desktops (Chrome OS), embedded devices, and much more.

Linux has become so dominant in the enterprise space that even Microsoft is now investing in Linux; they have developed a Linux-based modular operating system for data center networking. The company is putting Linux and Windows on an even playing field by bringing Linux development tools to Windows and Windows development tools (e.g., PowerShell) to Linux.

Jim Zemlin, the executive director of the Linux Foundation, claims that Linux is the biggest shared technology, and he has stats to back it up. According to the latest Linux kernel development report published by the Linux Foundation, “since 2015 more than 14,000 individual developers from over 1,300 different companies have contributed to the kernel.”

The top 10+ companies that contribute to the development of the Linux kernel include Intel, Red Hat, Linaro, Samsung, SUSE, IBM, Renesas, Google, AMD, Texas Instruments, and ARM.

The size of the kernel has increased over the last 25 years. The first release of the kernel had more than 10,000 lines of code in 1991. Now the Linux kernel has more than 22 million lines of code.