What Are the Four Birthdays of Linux? Linus Torvalds Reveals the History

In an interview with ZDNet marking Linux’s 30th anniversary, Linus Torvalds discussed the operating system’s history and why he considers it to have four birthdays.

“The first news‑group post (August 25) is public, but version 0.01 (September 17) was never announced publicly; its date can only be inferred from the tar‑file timestamps. Both of these moments count as birthdays for me.”

He also mentioned two additional dates: the earliest semi‑public mention of Linux on July 3, when he first asked for POSIX documents on the Minix newsgroup, and the first full public announcement of version 0.02 on October 5.

Linus recalled early encouragement from professors at the University of Helsinki, noting that the university’s CS department was open to unofficial extracurricular projects, which helped Linux gain early traction.

By the end of 1991, Linux had already attracted more attention than the GNU Hurd or Minix. Linus explained that around Christmas 1991 he began experimenting with features Minix lacked, such as disk paging, leading to the jump from version 0.03 (≈ Nov 1991) to 0.12 (Jan 1992).

“The shift to GPLv2 was crucial. It isn’t the original license, but it’s a major reason Linux became so widespread.”

He emphasized the importance of corporate involvement, citing IBM, Oracle, and Red Hat as key players that co‑existed with the open‑source community.

Technical milestones he highlighted include early ports to other architectures (e.g., Linux/Alpha), the adoption of version‑control systems like BitKeeper, and the creation of Git, which transformed how the kernel source is managed.

“I only felt like a successful programmer after creating Git; it removed the fear that Linux was a one‑off project.”

Looking ahead, Linus, now 51, says he will continue to accompany Linux, joking that gardening is unlikely to replace his work.

He also acknowledged other influential early contributors such as Theodore Ts’o, James Bottomley, Gerald Pfeifer, and Greg Kroah‑Hartman.