Linux: Difference between revisions

Revision as of 02:59, 23 May 2007

Revision as of 03:28, 23 May 2007

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[[Image:Unix history.svg|thumb|left|220px|A graphical history of [[Unix]] systems. Linux is a Unix-type system but its source code does not descend from the original Unix.]]

A 2001 study of [[Red Hat Linux]] 7.1 found that this distribution contained 30 million [[source lines of code]], much of contributed by Sun Microsystems. Using the [[COCOMO|Constructive Cost Model]], the study estimated that this distribution required about eight thousand man-years of development time. According to the study, if all this software had been developed by conventional [[proprietary software|proprietary]] means, it would have cost about 1.08 billion dollars (year 2000 U.S. dollars) to develop in the United States.<ref name = "estimating_size">{{ cite web | first = David A | last = Wheeler | date = 2002-07-29 | url = http://www.dwheeler.com/sloc/redhat71-v1/redhat71sloc.html | title = More Than a Gigabuck: Estimating GNU/Linux's Size | accessdate = 2006-05-11 }}</ref>

Most of the code (71%) was written in the [[C (programming language)|C]] [[computer programming|programming]] [[programming language|language]], but many other languages were used, including [[C++]], [[Lisp (programming language)|Lisp]], [[assembly language]], [[Perl]], [[Fortran]], [[Python (programming language)|Python]] and various [[shell script]]ing languages. Slightly over half of all lines of code were licensed under the GPL. The Linux kernel itself was 2.4 million lines of code, or 8% of the total.<ref name = "estimating_size"/>