Editing Top (software) (section)

==Implementations==
There are several different versions of top. The traditional Unix version was written by William LeFebvre and originally copyrighted in 1984.<ref>{{Cite web|url=http://www.unixtop.org/license.shtml|archive-url=https://web.archive.org/web/20080413180808/http://www.unixtop.org/license.shtml|url-status=dead|archive-date=2008-04-13|title=Documentation|website=Unix Top|access-date=2016-05-22}}</ref> It is hosted on [[SourceForge]],<ref>{{Cite web|url=http://www.unixtop.org/faq.shtml#title1|archive-url=https://web.archive.org/web/20040420005914/http://www.unixtop.org/faq.shtml#title1|url-status=dead|archive-date=2004-04-20|title=About Top|last=LeFebvre|first=William|date=2014-09-16|website=Unix Top|access-date=2016-05-22}}</ref> and release 3.7 was announced in 2008.<ref>{{Cite web|url=https://sourceforge.net/p/unixtop/news/?source=navbar|title=Top / News|website=SourceForge|access-date=2016-05-22}}</ref>

The Linux version of top is part of the [[procps-ng]] group of tools. It was originally written by Roger Binns<ref>{{Cite web|url=http://linux.die.net/man/1/top|title=top(1): tasks - Linux man page|website=Linux Documentation|access-date=2016-05-22}}</ref> and released in early 1992 but shortly thereafter taken over by others.<ref>{{Cite web|url=http://www.rogerbinns.com/blog/linux-top-origins.html|title=Linux Top Origins {{!}} Roger's world|last=Binns|first=Roger|website=Roger's world|access-date=2016-05-22}}</ref>

On [[Solaris (operating system)|Solaris]], the roughly equivalent program is prstat. [[Microsoft Windows]] has the [[tasklist]] command and the graphical [[Task Manager (Windows)|Task Manager]] utility. [[IBM AIX]] has an updating running processes list as part of the topas and [[topas_nmon]] commands.

The load average numbers in Linux refers to the sum of the number of processes waiting in the run-queue plus the number currently executing. The number is absolute, not relative. And thus it can be [[Bounded function|unbounded]]; unlike utilization. The instant variations of the number of processes are [[Damping ratio|damped]] with an [[exponential decay]] formula which is calculated using [[Fixed-point arithmetic|fixed point]] math.<ref name="tq_ldavg2">{{cite web|url=http://www.teamquest.com/pdfs/whitepaper/ldavg2.pdf|title=UNIX Load Average Part 2: Not Your Average Average|last=J. Gunther|first=Neil|year=2010|publisher=teamquest.com|accessdate=2013-06-10|archive-url=https://web.archive.org/web/20120602093128/http://www.teamquest.com/pdfs/whitepaper/ldavg2.pdf|archive-date=2012-06-02|url-status=dead}}</ref>

The [[ps (Unix)|ps]] program is similar to top, but instead produces a snapshot of processes taken at the time of invocation. top's {{mono|n}} (number of iterations) option can product a similar result, causing the program to run the specified number of iterations, then exit after printing its output.