free software: history, perspectives and implications

Free Software: History, Perspectives and Implications

'Source Code' – Human readable documents that define a program's logic.

Example:

sub login { my $login = shift; my $password = shift;

my $user = User->new();

my $query="Select id from User where login=? AND password=?"; my $id = $user->dbread('', $query, $login, $password); if ($id) { $user = $user->lookup($id->[0]); $user->{'session'} = &getSession; $user->save; return $user; } else { return; }

}

Early Software Development

● Specialized, expensive computers● Run by highly-skilled technicians● Extensive programming was required even

for simple tasks● Sharing of source code was commonplace

Creation of Software Industry

● Computer hardware became more powerful● Allowed for more complex software● Relative value of software increased, as cost

of hardware decreased● Technology companies begin to restrict their

software

GNU Project

● GNU's Not Unix● Create Fully Free Operating System● Unix base meant tools could be run on many

different types of computers

GNU General Public License

● Protects software from further restrictions● 'copyleft'● 'Free as in Speech, Not as in Beer'

Cathedral vs. Bazaar Models

Cathedral Model● Centralized

Development● Few core

developers● Only release stable

code

Bazaar Model● De-centralized● Many developers● Open process● Frequent releases

Use of Free Software

● Linux 'Clusters'– Many computers acting as one– 49 of 500 top supercomputers run free software– Also used in movie CGI: Titanic, Phantom

Menace, Lord of the Rings made using Linux

●Recipe Analogie●Explanation of Programming●Show some source code●History

●Early days – pre software industry●Stallman anecdote●GPL

●Free as in Freedom●Linux●Widespread use of free software

●Benefits●Cathedral vs. Bazaar●Software is consumer-driven, not profit driven●Given enough eyes, all bugs are shallow

●Motivations●Identity●ego/reputation●For pay

●Oss business models●Urge to create

●Implications●New Class Theory●Progressive uses

●Schools●Governments●Developing nations

●Intellectual Property