Sometime in 2016 Linux will be 25 years old. Exactly when is a matter of opinion.

We could consider Linux's 25th birthday to be August 25th. That's because on that date in 1991, Linus Torvalds made his announcement to the minix community to let them know that he was working on a modest new OS. He had started the work in April. By October 5th, he felt that his new OS was usable and ready for the community at large.

Whether you count the announcement (8/25/1991), its readiness for use/testing (10/05/1991), or Linus' initially getting his project off the ground (April 1991) as the official birthday, Linux turns 25 sometime this year. And what is most amazing is what has happened since. All manner of Linux OSes have come into being.

If I'm counting correctly, Wikipedia lists 258 distributions! From Alpine to ZipSlack, Linux has proliferated faster than anyone imagined, capturing the excitement of some of the world's most creative programmers and gaining some of the most devoted followings that computing technologies have ever known.

In his August 1991 email, Linus announced his project with a very modest "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since April, and is starting to get ready." Little did anyone at that time imagine how popular and important Linux would become or how many directions it would take.

That "not big and professional" statement is obviously so remote from what Linux has become that it's almost hard to imagine just how Linux took off the way it did. Today, Linux resides on the tiniest and most limited systems as well as large, complex, servers. It sits on an uncountable number of desktops and has even led to the creation of the Android OS (based on Linux) which lives on so many of our phones and tablets.

Because Linux is, for the most part, not licensed, no one seems to have a good estimate of how many systems today are running some version of it. Some versions, like the "enterprise" versions of Red Hat and Suse, are licensed, but these add up to an extremely small percentage of the systems in use today. How many Linux systems are running today? No one knows. And no one has a very good guess either.

Even I had no idea, until I started checking and found the Wikipedia page, how many types and versions of Linux have come into being. Some have come and gone, but the number of distributions that are still viable and in use is quite amazing. According to the Wikipedia categories, we have these counts:

43 3rd Party 5 Arch 50 Debian 21 Fedora 12 Gentoo 49 independent 3 Knoppix 5 Madriva 3 openSuse 3 Pacman 10 RHEL 13 RPM 20 Slackware 4 Slax 17 Ubuntu 258 total

It is quite remarkable that so much came from a project that started out so modestly. Linus' early efforts and the participation of more than 10,000 programmers have had a huge impact on the computer industry and on how so many of us work today.

The Wikipedia page breaks its list of Linux distributions into a number of different categories or families based on the major distributions. Many fall into well known and very large Linux families -- Debian, Fedora, Ubuntu, Red Hat, Slackware -- while others are in smaller clusters. But all have their followings. How many would you recognize? Want to see if you can identify twenty-five distributions selected from the 258? Check my next post for a little slideshow quiz.

I don't know about you, but I'm very excited when I take a look around and get a feel for the impact that Linux has had. If you haven't celebrated already, you might put August 25th or October 5th on your calendar.

Get ready to wish Linux a very happy 25th!