3 articles to give you a good summary of open source licenses, the differences, and when to use which one.

The major ones in use are GPL License, MIT License, BSD License, LGPL License.

• http://www.patrick-wied.at/blog/how-to-correctly-use-code-you-didnt-write/
• http://www.smashingmagazine.com/2010/03/24/a-short-guide-to-open-source-and-similar-licenses/
• http://khason.net/blog/open-source-licenses-comparison-table/