More OS

What is Linux, anyway? Here is our explanation.

When was Unix created? Like Mac OS X, Linux is a flavor of Unix which was invented more than 40 years ago in the late 60′s and early 70′s by AT&T and evolved with the help of MIT, UC Berkeley and many different companies for scientific and professional supercomputer users who wanted a very powerful and flexible OS. Some of these different versions were required by differing use of copyright law as it applies Linux and the software programs that run on it have evolved a lot from their more technical roots and are now very easy to use.

One example of the approach taken by Unix is the use of system time. A precise way to keep track of time is to count the number of seconds from a reference point, and Unix and it’s derivatives have chosen Jan 1, 1970 in the UTC time zone as it’s reference. This may sound odd for humans but is perfectly logical and practical for computers. The relative way in which human beings tell time is logical and practical for us, so conversions are done using our relatively convoluted rules when needed.

Freedom to do what you want with your computer, including understanding and modifying all of the software parts has been important for decades. There are some parallels with the demands for transparency expressed in the Occupy demonstrations.

When was Linux created? Linux is most common on servers but is increasingly popular on personal computers. The different versions together are sometimes called Unix-Like or *nix. Parts of the systems we now use were first created in 1983 and 1991 and because many people have needed a good operating system they shared it. People continue to contribute to Linux because they need the improvements themselves and benefit when others share their improvements as well, though this virtuous cycle must begin with trust and understanding of how programs.

When did Linux celebrate its 20th birthday? 2011!

What other types of Linux are available?

One of the advantages and apparent disadvantages of "Linux" is choice! It is difficult to be precise without explaining a few things and going a bit into the history and evolution of the technology. To people who know the differences, when newcomers say "Linux" it is commonly assumed that most people approximately are talking about a Unix like Linux Distribution created using GNU software.

Good lists of the many different distributions available are on distrowatch.com, wikipedia list & wikipedia comparison. Some of the UNIX like systems we have discussed at dvlug.org include:
Tux

  • Debian family with SPI-Inc ( Ubuntu is highly recommended for beginners, Kubuntu, Xubuntu, Edubuntu, Lubuntu, Mythbuntu, Ubuntu Studio, Mint, Backtrack, Crunchbang, Qimo, gNewSense assisted by the FSF/GNU project but currently “dormant”. Xandros was previously Corel, purchased Linspire/LindowsOS
  • Red Hat family lead by Red Hat, Inc. from North Carolina ( Red Hat Enterprise Linux (RHEL), CentOS, Fedora, Scientific Linux, Mandriva (formerly Mandrake of Paris, France and Conectiva of Curitiba, Brazil) )
  • Slackware family ( openSUSE, SUSE formerly a German company based in Nuremberg, then owned by Novell and now owned by Attachmate Group of Houston, TX )
  • Arch – uses the pacman file manager with a rolling release and a DIY ethic. Their approach is not recommended for beginners.
  • Gentoo uses the emerge/portage package manager (based on BSD ports) using a rolling release and a DIY ethic to provide a “meta distribution”. Instead of downloading pre-compiled software like most other distributions a gentoo computer downloads the source code of programs and compiles it during installation. This can take a significant amount of time. Their approach provides control over how programs are compiled and requires one to understand the tradeoffs in the choices.
  • BSD family (Darwin is the basis of Mac OS X. Free BSD traces its roots back to the original Berkeley Standard Distribution or “west coast” UNIX.)
  • Some diagrams help illustrate the relationships between the many Unix-like systems and Linux distributions. All “unix-like” systems evolved and have some kind of formal or informal relationship to the 1969 AT&T efforts and are a blend of BSD (west coast) UNIX and System V (MIT, east coast) UNIX. The GNU system was announced in 1983 by Richard Stallman while working at MIT but (still) lacks a stable kernel. The design chosen for the GNU Hurd kernel is very difficult to debug. GNU tools enabled the development of the Linux kernel announced in 1991 by Linus Torvalds while a student at the University of Helsinki. Linus is now a Fellow with the Linux Foundation in Portland, OR.