1. “The Open Source Initiative: Open Source Definition”, available at
http://www.opensource.org/docs/definition.html.
2. “The Linux Home Page at Linux Online”, http://www.linux.org/.
3. “The Apache Software Foundation”, http://www.apache.org.
4. “mozilla.org”, http://www.mozilla.org/.
5. H. Wang and C. Wang, “Open Source Software Adoption: A Status Report,” IEEE Software, March/April, pp. 90-95, 2001.
6. Open office information available at http://www.openoffice.org
7. SourceForge”, http://sourceforge.net/.
8. http://www.gnu.org/philosophy/categories.en.html
9. http://osswatch.jiscinvolve.org/wp/2015/02/05/open-source-software-licensing-trends/
10. http://www.wired.com/2015/01/open-source-database/
11. http://dazeinfo.com/2014/07/10/google-inc-goog-android-ios-windows-os-device-shipment-growth-2014-2015/
12. Benefits of Open Source softwares available at http://open-source.gbdirect.co.uk/migration/benefit.html
13. C. Dibona, M. Stone, and S. Ockman, Open Sources: Voices from the Open Source Revolution, O'Reilly & Associates, 1999.
14. Categories of Free and Non-Free Software”, http://www.gnu.org/philosophy/categories.html.