Ken Thompson is an American computer scientist who designed the original Unix operating system and invented the B programming language, the predecessor to C. Dennis Ritchie created the C language and collaborated with Thompson on Unix. Richard Stallman launched the GNU Project to develop a free Unix-like operating system and founded the Free Software Foundation. He pioneered the concept of copyleft through licenses like the GPL. Linus Torvalds created the Linux kernel, which combined with GNU software forms a fully functional operating system, and also created the Git version control system.

1. Linux and computing

2. Linux and computing
By : Khawar Nehal
Date : 28 September 2021

3. Ken Thompson
Kenneth Lane Thompson (born February 4, 1943)
is an American pioneer of computer science.
Thompson worked at Bell Labs for most of his
career where he designed and implemented the
original Unix operating system.
Thompson (left)
with Dennis
Ritchie

4. Ken Thompson
He also invented the B programming language,
the direct predecessor to the C programming
language, and was one of the creators and early
developers of the Plan 9 operating system.
Since 2006, Thompson has worked at Google,
where he co-invented the Go programming
language.

5. Ken Thompson
Other notable contributions included his work on
regular expressions and early computer text
editors QED and ed, the definition of the UTF-8
encoding, and his work on computer chess that
included the creation of endgame tablebases and
the chess machine Belle.
He won the Turing Award in 1983 with his long-
term colleague Dennis Ritchie.

6. Dennis Ritchie
Dennis MacAlistair Ritchie
(September 9, 1941 – c. October
12, 2011) was an American
computer scientist.
He created the C programming
language and, with long-time
colleague Ken Thompson, the
Unix operating system and B
programming language.

7. Dennis Ritchie
Another historical note.
The C Compiler shall create the file named a.out
because before C there was B and even before
that there was the A programming language and
that is the default executable file name for A
programming language compiler’s executable file.

8. Dennis Ritchie
Ritchie and Thompson were awarded the Turing
Award from the ACM in 1983, the Hamming Medal
from the IEEE in 1990 and the National Medal of
Technology from President Bill Clinton in 1999.
Ritchie was the head of Lucent Technologies
System Software Research Department when he
retired in 2007. He was the "R" in K&R C, and
commonly known by his username dmr.

9. Richard Stallman
Richard Matthew Stallman (/ st lm n/; born
ˈ ɑː ə
March 16, 1953), also known by his initials, rms, is
an American free software movement activist and
programmer.
He campaigns for software to be distributed in a
manner such that its users receive the freedoms
to use, study, distribute, and modify that software.
Software that ensures these freedoms is termed
free software.

10. Richard Stallman
Stallman launched the GNU
Project, founded the Free
Software Foundation,
developed the GNU
Compiler Collection and
GNU Emacs, and wrote the
GNU General Public
License.

11. Richard Stallman
Stallman launched the GNU Project in
September 1983 to write a Unix-like computer
operating system composed entirely of free
software.
With this, he also launched the free software
movement.

12. Richard Stallman
He has been the GNU project's lead architect
and organizer, and developed a number of pieces
of widely used GNU software including, among
others, the GNU Compiler Collection, GNU
Debugger, and GNU Emacs text editor.
In October 1985 he founded the Free Software
Foundation (FSF).

13. Richard Stallman
Stallman pioneered the concept of copyleft,
which uses the principles of copyright law to
preserve the right to use, modify, and distribute
free software, and is the main author of free
software licenses which describe those terms,
most notably the GNU General Public License
(GPL), the most widely used free software
license.

14. Richard Stallman
In 1989, he co-founded the League for
Programming Freedom. Since the mid-1990s,
Stallman has spent most of his time advocating
for free software, as well as campaigning against
software patents, digital rights management
(which he refers to as digital restrictions
management, calling the more common term
misleading), and other legal and technical
systems which he sees as taking away users'
freedoms.

15. Richard Stallman
This has included software license agreements,
non-disclosure agreements, activation keys,
dongles, copy restriction, proprietary formats,
and binary executables without source code.

16. Linus Torvalds
Linus Benedict Torvalds (/ li n s t rv ldz/ LEE-
ˈ ː ə ˈ ɔː ɔː
n s TOR-vawldz, Finland Swedish: [ li n s
ə ˈ ː ʉ
tu rv lds] (About this soundlisten); born 28
ˈ ː ɑ
December 1969) is a Finnish-American software
engineer who is the creator and, historically, the
main developer of the Linux kernel, used by
Linux distributions and other operating systems
such as Android.

17. Linus Torvalds
He also created the
distributed version
control system Git and
the scuba dive logging
and planning software
Subsurface.

18. Linus Torvalds
He was honored, along with Shinya Yamanaka,
with the 2012 Millennium Technology Prize by the
Technology Academy Finland "in recognition of
his creation of a new open source operating
system for computers leading to the widely used
Linux kernel."
He is also the recipient of the 2014 IEEE
Computer Society Computer Pioneer Award and
the 2018 IEEE Masaru Ibuka Consumer
Electronics Award.