Patent There is no universal definition. Functional expression of an idea - not the idea itself. It is given by a state for a limited period of time. It restricts other from using the invention without the permission of patent holder.
License A license is a kind of a permission. Patent holder can grant permission to use his/her patent by licensing it to others. Software companies/creators license software to others for using. License can cover special agreements like warranties.
Copyright Copyright prevents unauthorized copy. Authors can protect their writings, photographers can protect their photography. Software can be copyrighted to prevent unauthorized copying of software. Software in public domain cannot be copyrighted.
Copyleft Copyleft license is a copyright license. Copyleft enable the user to copy, distribute and modify the work. Modified/derived works should be distributed with the same terms as the main work.
Some Open SourceLicenses GNU GPL GNU LGPL GNU AGPL MIT License BSD License MPL License
GNU GPL Written by Richard Stallman Free and open-source license Copyleft License 3 versions released Many open source software use open source license Most notably, Linux
GNU GPL GPL addressed two problems in software freedom. First problem and solution Software were distributed as binary only, no one can edit. GPLv1 said that the source code must be available under the same license.
GNU GPL (cont.) Second problem and solution Free software was being combined with restricted software restricting software freedom GPLv1 said software distributed with GPLv1 licensed software must have the same permission as GPLv1
BSD License There are many versions – Modified BSD License is most common. Free and open-source license. There are also Original BSD License and Free BSD License. Permissive License - works based on the material may be released under a proprietary license or as closed source software. Notable software – NetBSD, FreeBSD
MIT License MIT License is almost as same as BSD License. Does not contain the term prohibiting the use of the name of the copyright holder in promotion of derivative work. Notable software – X Windowing System, Mono Development
MPL Mozilla Public License Most Mozilla Software, Adobe Flex, Open Solaris use it Copyleft License It’s licensing is in two parts – initial author’s right and other people’s rights Can be combined with proprietary software
AGPL Affero General Public License Mainly used for web services or SaaS model Web services under should provide a link to download the source code
LGPL LGPL is used for software libraries It allows other software to link with the library All other restrictions from GPL are also in LGPL
Creative CommonsAttribution Used to share creative works like texts, photography, etc. Version 3 is used in Wikipedia. This license allows to share, remix, and make commercial use of the work You must attribute the work in the manner specified by the author or licensor First version didn’t allowed derivative works and commercial use