Data Mining Dr. Mohsen Kahani Email: [email protected]@um.ac.ir kahani
Open Source Software Presented by: Dr. Mohsen Kahani kahani
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Transcript of Open Source Software Presented by: Dr. Mohsen Kahani kahani
Open Source Open Source SoftwareSoftware
Presented by:
Dr. Mohsen KahaniDr. Mohsen Kahanihttp://www.um.ac.ir/~kahani/
ContentsContents
IntroductionWhat is OSS?Why OSS?OSS Economy and GovernanceFamous OSS ProjectsOSS repository sitesConclusion
IntroductionIntroduction
Everybody likes free softwareInternetInternet has eased distribution of free
SoftwareLicensing model for software products:
– Commercial – Shareware – Open source
What is OSS?What is OSS?
Open source doesn't just mean access to the source code
OSS is software distributed under a license which meets some criteria in general:– free to redistribute– source code must be freely available– modifications and derivative works allowed– no restrictions on who uses the code
Most widely used licenses:– GNU General Public License (GPL)– BSD, MIT X license, etc.
OSS LicenseOSS License(www.opensource.org)(www.opensource.org)
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. The License Must Not Restrict Other Software
Historical HighlightsHistorical Highlights
1979 BSD license1984 AT&T commercializes Unix1984 Richard Stallman organizes GNU1984 MIT X1989 GPL1991 Linus Torvalds releases Linux1998 Netscape announces open source98-99 IBM, HP, Oracle, Corel Supports
Why OSS?Why OSS?
Quantitative Vs. Qualitative DiscussionQuantitative Measures:
– Market shareMarket share– ReliabilityReliability– PerformancePerformance– ScalabilityScalability– SecuritySecurity– Total Cost of Ownership (TCO)Total Cost of Ownership (TCO)
Market ShareMarket Share
Market Share for Top Web Servers, Aug 95 – Nov. 2001
Linux is #2 Web Server OS After Windows (49% vs. 29%)
ReliabilityReliability
Of the 50 sites with the highest uptimes – 92% use Apache– 50% run on OSS operating systems
IIS-based sites have more than double offline time (on average) than Apache
Linux is more reliable than Windows NT/2000
PerformancePerformance
Linux/Apache 16%-50% faster than NT/IISeWeek Survey:
MySQL equal performance as Oracle, outperforms others
ScalabilityScalability
Linux support a wider range of platforms than any other OS
OSS development processes can scale to develop large software systems
– Red Hat Linux 7.1, has over 30 million SLOC, representing 8,000 person-years or $1 billion
SecuritySecurity
Difficult to measure security with numbers Attrition.org's survey:
– Defaced systems: 59% Windows / 21% Linux
“hacker insurance” costs 5-15% more for Windows vs. Linux
IIS was attacked 1,400 times more frequently than Apache in 2001
Total Cost of OwnershipTotal Cost of Ownership
OSS costs less to initially acquire OSS often use older hardware more
efficiently The supporting cost is nearly the same 2001 InfoWorld survey:
– 32% over $250,000 per year– 60% over $50,000 per year
Qualitative DiscussionQualitative Discussion
Iterative and incremental development Potential to revolutionize the entire
software industry No risk of single source solutions Greater flexibility Platform independency
Problems (perceived or real)Problems (perceived or real)
Lack of supportLower quality software / programmersNot ready for enterprise level operationsNot user friendlyMissing applications
Software EconomySoftware Economy Commercial
– Proprietary control of code allows it to generate income, which can be used to compensate programmers.
– Greater control in allocation of specific resources– Costs associated with the need for secrecy in development of code
and for copy protection efforts Open Source
– Reduced revenues when code is given away– Reduced costs associated with
“Alumni effect”: Freely available code gets incorporated in teaching activities, which leads new generations to adopt the same software, reducing downstream training costs. (Unix)
Customization and bug-fixing: Direct external benefit associated with parallel development and innovation
Transparency of process and functionality Full initiative Minimal lock-in
OSS Governance IssuesOSS Governance Issues
Large open source projects need leadership and rules to avoid splintering
Leadership activities– Provide a vision of the end result(s) of the project
Assemble a critical mass of initial code to demonstrate value of the project and promise for the future
– Organize production modules Components must be doable and contribute to the overall project
– Attract programmers to the project Ensure that component modules provide sufficient challenge
– Hold project together Be able to make hard-nosed decisions about which components end up
being part of the “official” version of the software
Governance– Single strong leader (Torvalds with Linux)– Governance committee
OSS Commercial StrategiesOSS Commercial Strategies
– Provision of complementary products and services Documentation Installation and configuration wizards Support
– Provision of expertise in support of open source projects
– Intermediation between corporate clients and open source community
Certification Conduit to venture capital community Example: Collab.Net
Who Makes OSS?Who Makes OSS?
Public Sector– Everybody should use software generated from
people’s money (eg. GreenStone Digital Library)
Big Companies– Generate income from support (eg. Redhat)– Control Market, sell other products (eg. IBM)
Individual freelance programmer– Altruism– Becoming famous
LinuxLinux
Started by Linus Torvalds in 1991 as a UNIX clone
Several distributions are available: Red Hat, Debia, Suse, Mandrake …
Red Hat 9 is very reliable, easy to install and use
Special purpose distributions also available
Started by patching NCSA HTTPDThe most widely used web serverAvailable for most platformsCan be expanded through modulesIs supported by Apache company
The most popular Open Source SQL-based relational database
Fast, multi-threadedMySQL vs MySQL MaxPlatform IndependentNewest version (V4.0) provides most
features of expensive commercial DBMSs
HyperText Pre-ProcessorHTML-embedded scripting languageObject-Oriented / Syntactically similar to CWell suited for Web applicationsTwo many utilities/add-ons availableMakes development process fast and easy
OSS futureOSS future
High quality office suites availableMore mission-critical applications availableClustering / high availabilityIncrease in the number of service providersSteady increase in the use of Linux
Some RemarksSome Remarks
Stick to mature, highly visible OSS products Too many alternatives; difficult to choosePlan for support / educationMore difficult to manage
ConclusionConclusion
OSS has become a major player in computer industry
OSS seems a better solution in many casesMany big organization are using OSSOSS options should be carefully considered
for any project.The future looks bright