1 Open Source Code Steve Chenoweth CSSE 375, Rose-Hulman Based on Don Bagert’s 2006 Lecture

2 Today Open Source - this Open Source - this Maintenance Case Study, as a team, with Quiz 8. Maintenance Case Study, as a team, with Quiz 8. Turn in HW3: Detailed Design,11:55 PM today. Turn in HW3: Detailed Design,11:55 PM today. Readings for tomorrow – See Friday, slide 3 for list. Readings for tomorrow – See Friday, slide 3 for list. Thursday – Next team progress report (with a Wed night turn-in) Thursday – Next team progress report (with a Wed night turn-in)

3 References Open Source Initiative site Open Source Initiative site Eric S. Raymond’s “Revenge of the Hackers” Eric S. Raymond’s “Revenge of the Hackers” Linux website Linux website SourceForge SourceForge

4 Outline Origins of Open Source Origins of Open Source Open Source Definition Open Source Definition Sample Open Source License: GNU Sample Open Source License: GNU Sample Site: SourceForge Sample Site: SourceForge

5 Origins of Open Source – 1/5 Unix Unix –Developed at AT&T in 1971 –Could not be sold due to monopoly restrictions on AT&T –Given free to universities along with the source code and a commentary on it Unix co-founder Ken Thompson perpetrates chess fraud in 1980 – see s/column.asp?pid= s/column.asp?pid=190

6 Origins of Open Source – 2/5 Original Unix target – replace some of the work done by mainframes with Unix-based mid-range servers. Original Unix target – replace some of the work done by mainframes with Unix-based mid-range servers. Typical implementation – time sharing terminals for college students and researchers. Typical implementation – time sharing terminals for college students and researchers. Right - DCS Systime 5000 (PDP11/70) used for Unix Development. From computing.org.uk/acd/sus/perq_history/ part_5/c21.htm. computing.org.uk/acd/sus/perq_history/ part_5/c21.htm

7 Origins of Open Source – 3/5 Unix (continued) Unix (continued) –Monopoly restrictions lifted in 1983 –UNIX (and C) now became hot properties Source code no longer available, though Source code no longer available, though –C++ - mid 1980’s Stroustrup’s idea of an “open library” of classes Stroustrup’s idea of an “open library” of classes Stroustrup –Versions of “Unix-like” systems began to appear Most prominent: Linux (1991) – development led by Linus Torvalds Most prominent: Linux (1991) – development led by Linus Torvalds Above – The founder of C++ today.

8 Origins of Open Source – 4/5 The developers of Linux defied many of the then-current software development conventions: The developers of Linux defied many of the then-current software development conventions: “Even though I had been active in the hacker culture* for many years, I still carried in my head the unexamined assumption that hacker amateurs, gifted though they might be, could not possibly muster the resources or skill necessary to produce a usable multitasking operating system…But where they failed, Linus Torvalds and his community succeeded. And they did not merely fulfill the minimum requirements of stability and functioning Unix interfaces. No. They blew right past that criterion with exuberance and flair, providing hundreds of megabytes of programs, documents, and other resources. Full suites of Internet tools, desktop-publishing software, graphics support, editors, games...you name it.” - Eric S. Raymond, “Revenge of the Hackers” *See also Hackers: A unique new breed of American Hero, by Steven Levy, Dell, 1984, ISBN

9 Origins of Open Source – 5/5 The success of Linux inspired the creation of the Open Source Initiative (OSI) in 1998 The success of Linux inspired the creation of the Open Source Initiative (OSI) in 1998 –Endorsed by Linus Torvalds –Leading proponent: Eric S. Raymond –Developed the Open Source Definition Open Source DefinitionOpen Source Definition

10 Open Source Definition 1. Free Redistribution 2. Source Code 3. Derived Works 4. Integrity of the Author's Source Code 5. No Discrimination Against Persons or Groups 6. No Discrimination Against Fields of Endeavor 7. Distribution of License 8. License Must Not Be Specific to a Product 9. License Must Not Restrict Other Software 10. License Must Be Technology-Neutral

11 Sample Open Source License: GNU General Public License (GPL) One of those approved by OSI as following the Open Source Definition One of those approved by OSI as following the Open Source Definition –

12 Sample Site: SourceForge Hosts more than 100,000 projects Hosts more than 100,000 projects Services Provided: Services Provided: Services Provided: Services Provided: –Open Source Software (OSS) and Community –Web Tools for Community and Project Management –File Release System –Donation System –Compile Farm –CVS Service –Subversion Service –Communication Tools –Publicity –Project Web Service

13 Hands-On: SourceForge Ok, you already did this… Let’s look at the case study…