Editing Lex (software) (section)

==History==
Lex was originally written by [[Mike Lesk]] and [[Eric Schmidt]]<ref>{{cite web|first1=M.E. |last1=Lesk |first2=E. |last2=Schmidt |title=Lex – A Lexical Analyzer Generator|archive-url=https://archive.today/20120728112736/http://dinosaur.compilertools.net/lex/index.html|archive-date=2012-07-28|url-status=dead|url=http://dinosaur.compilertools.net/lex/index.html|access-date=August 16, 2010}}</ref> and described in 1975.<ref>{{cite web|url=http://epaperpress.com/lexandyacc/download/lex.pdf |title=Lex – A Lexical Analyzer Generator |first1=M.E. |last1=Lesk |first2=E. |last2=Schmidt |date=July 21, 1975| work=UNIX TIME-SHARING SYSTEM:UNIX PROGRAMMER’S MANUAL, Seventh Edition, Volume 2B |publisher=bell-labs.com|access-date= Dec 20, 2011}}</ref><ref>{{cite journal |last1=Lesk |first1=M.E. |date=October 1975 |title=Lex – A Lexical Analyzer Generator |journal=Comp. Sci. Tech. Rep. No. 39 |location=Murray Hill, New Jersey |publisher=Bell Laboratories}}</ref>
In the following years, Lex became the standard lexical analyzer generator on many [[Unix]] and [[Unix-like]] systems. In 1983, Lex was one of several UNIX tools available for Charles River Data Systems' [[UNOS (operating system)|UNOS]] operating system under [[Bell Laboratories]] license.<ref>{{Cite book|year=1983|title=The Insider's Guide To The Universe|publisher=Charles River Data Systems, Inc.|url=https://www.1000bit.it/ad/bro/charles/CharlesRiverSystem-Universe.pdf|page=13}}</ref>
Although originally distributed as proprietary software, some versions of Lex are now [[open-source software|open-source]]. Open-source versions of Lex, based on the original proprietary code, are now distributed with open-source operating systems such as [[OpenSolaris]] and [[Plan 9 from Bell Labs]]. One popular open-source version of Lex, called [[flex lexical analyser|flex]], or the "fast lexical analyzer", is not derived from proprietary coding.