#1 First Berkeley Software Distribution (1BSD) Unix
Came into existence: March 9, 1978
It was not Linux which that was the first open-source operating system; the honor goes to Bill Joy’s first version of BDS Unix. When Unix first showed up in 1969, it was open source, it was closed later, but it kept the free software flag flying. Though Linux enjoyed the lime light, Unix was important too.
BSD is a Unix operating system derivative developed and distributed by the Computer Systems Research Group (CSRG) of the University of California, Berkeley. Today the term "BSD" is often used non-specifically to refer to any of the BSD descendants which together form a branch of the family of Unix-like operating systems. Operating systems derived from the original BSD code remain actively developed and widely used.
#2 VistA
Came into existence: 1975
The oldest open-source program which is still commonly used is VistA. The Veterans Health Information Systems and Technology Architecture (VistA) is an enterprise-wide information system built around an Electronic Health Record (EHR), used throughout the United States Department of Veterans Affairs (VA) medical system, known as the Veterans Health Administration (VHA).
#3 BRL-CAD
Came into existence: Dec 16, 1983
BRL-CAD, Ballistic Research Laboratory-computer-aided design, is a constructive solid geometry (CSG) solid modeling computer-aided design (CAD) system. It includes an interactive geometry editor, ray tracing support for graphics rendering and geometric analysis, computer network distributed framebuffer support, scripting, image-processing and signal-processing tools. This program, which is still being worked on today, is used by the U.S. military to model ballistic attacks on vehicles.
#4 X Window System
Came into existence: 1983
At the same time that Emacs and gcc started to roll, others at MIT were working on the X Window System. The X Window System is a computer software system and network protocol that provides a basis for graphical user interfaces (GUIs) and rich input device capability for networked computers. No one knew it at the time that X Window would eventually become the basis for all important Linux and Unix interfaces, and the foundation for the Mac OS X
#5 GNU Emacs
Came into existence: 1984
Emacs and its derivatives are a family of text editors that are characterized by their extensibility. GNU Emacs is an extensible, customizable text editor—and more. At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing.
#6 GNU C compiler (gcc)
Came into existence: March 22, 1987
The GNU Compiler Collection (GCC) is a compiler system produced by the GNU Project supporting various programming languages. GCC has been adopted as the standard compiler by most other modern Unix-like computer operating systems, including Linux, and the BSD family. GCC is also available for most embedded platforms, including Symbian (called gcce), AMCC and Freescale Power Architecture-based chips. The compiler can target a wide variety of platforms, including videogame consoles such as the PlayStation 2 and Dreamcast.
Stallman was listed as the author but cited others for their contributions, including Jack Davidson and Christopher Fraser for the idea of using RTL as an intermediate language, Paul Rubin for writing most of the preprocessor and Leonard Tower for "parts of the parser, RTL generator, RTL definitions, and of the Vax machine description."
#7 Perl
Came into existence: December 18, 1987
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, it is considered to stand for “Practical Extraction and Reporting Language.” Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions.
Perl borrows features from other programming languages including C, shell scripting (sh), AWK, and sed. The language provides powerful text processing facilities without the arbitrary data-length limits of many contemporary Unix tools, facilitating easy manipulation of text files.
Perl gained widespread popularity in the late 1990s as a CGI scripting language, in part due to its parsing abilities. In addition to CGI, Perl is used for graphics programming, system administration, network programming, finance, bioinformatics, and other applications.
#8 GNU C Library (glibc)
Came into existence: February 1988
C programming language remains a vital language in open-source circles and to do much with C you need a good, general purpose library. The GNU C Library, commonly known as glibc, is the GNU Project's (The GNU Project is a free software, mass collaboration project, announced on 27 September 1983, by Richard Stallman at MIT) implementation of the C standard library. glibc was written by Roland McGrath, working for the Free Software Foundation (FSF) in the 1980s. By early 1988, McGrath had given what would become glibc, "a nearly complete set of ANSI C library functions." From this work would spring innumerable programs including Linux.
#9 Python
Came in to existence: February 20, 1991
Guido van Rossum, Python's creator, began work on this importantprogramming language in December 1989. It wasn't until February 1991, that it saw the light. Python is a general-purpose, interpreted high-level programming language whose design philosophy emphasizes code readability. Its syntax is said to be clear and expressive. Python has a large and comprehensive standard library.
Python supports multiple programming paradigms, including object-oriented, imperative and functional programming styles. It features a fully dynamic type system and automatic memory management, similar to that of Scheme, Ruby, Perl, and Tcl. Like other dynamic languages, Python is often used as a scripting language, but is also used in a wide range of non-scripting contexts.
According to Black Duck Software's Ohloh programming statistics, "Python is the fastest growing language in the open source world as measured by number of contributors."
Even Microsoft provides a Python IDE (integrated development environment ) for Visual Studio.
#10 Linux
Came into existence: August 25, 1991
Linux is a Unix-like computer operating system. The defining component of Linux is the Linux kernel, an operating system kernel first released in 5 October 1991 by Linus Torvalds. Torvalds wrote "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones" to the Minix Usenet group, and unknowingly, started the operating system juggernaut. This OS later became the most successful of open-source programs.
It is a leading operating system on servers and other big iron systems such as mainframe computers and supercomputers. Linux also runs on embedded systems such as mobile phones, tablet computers, network routers, televisions and video game consoles; the Android system in wide use on mobile devices is built on the Linux kernel.
