6. Computer History - MainFrame
http://en.wikipedia.org/wiki/Image:Honeywell-
Bull_DPS_7_Mainframe_BWW_March_1990.jpg (GFDL)
7. Source Code
âą Computer Instructions are coded in binary
format 00101...
âą A more human friendly method to program
computer:
/* Hello World program */
#include<stdio.h>
main()
{ printf("Hello World"); }
8. Source Code (Cont.)
âą Convert source code into binary instructions by
a computer compiler
âą Vertical market â one supplier for all computer
needs
âą Source code by itself own had no commercial
value -> freely distributed
11. Changes in Computer Industry
âą Personal computers - hardware and software
could be sold separately
âą Money could be made by closing up source
code
âą Some programmers sold the copyright of the
source code of collaborative projects and stole
of work of others
âą AT&T Unix incident
13. Responses to the Theft
âą Release source code that could not be used
commercially
âą Release source code that must remain freely
available -> Software Freedom
âą 1983 GNU project, Unix Clone
âą 1985 Free Software Foundation, Free as in
Free Speech, General Public License (GPL)
14. Free/Open Source Software
20+ Years Down the Road
âą Linux
IDC's Worldwide Quarterly Server Track
â2008 2Q $13.9 billion total
âMicrosoft $5.1 billion 36.5% Growth -1.7%
âLinux $1.9 billion 13.4% Growth 9.4%
(http://practical-tech.com/infrastructure/linux-server-share-
keeps-growing/)
15. Free/Open Source Software
20+ Years Down the Road
âą Apache
âMost popular web server
âAlways more popular than IIS
(http://www.netcraft.com/)
âą Foundation of Web 2.0
âFacebook: Apache PHP
âTwitter: Ruby on Rails