Following on from the success of the Google Summer of Code program, Google is pleased to announce this new effort to get young people involved in open source development. We've teamed up with the open source projects listed here to give student contestants the opportunity to learn more about and contribute to all aspects of open source software development, from writing code and documentation to preparing training materials and conducting user experience research.
If you're a student age 13 or older who has not yet begun university studies, we'd love to see you help out these projects. In return, you'll learn more about all aspects of developing software - not just programming - and you'll be eligible to win cash prizes and the all important t-shirt! You will, of course, need your parent or guardian's permission to participate where applicable.
Perens' principles
See Open Source Definition for the exact operational definition and examples of licenses that satisfy, and do not satisfy, those principles.
Under Perens' definition, open source describes a broad general type of software license that makes source code available to the general public with relaxed or non-existent copyright restrictions. The principles at stated say absolutely nothing about trademark or patent use and require absolutely no cooperation to ensure that any common audit or release regime applies to any derived works. It is an explicit "feature" of open source that it may put no restrictions on either the use nor redistribution nor the organization or user whatsoever.
It forbids, in principle, to guarantee continued access to derived works even by the major original contributors. In contrast to free software or open content licenses, which are often confused with open source but have much more rigorous rules and conventions, open source deliberately errs in favour of allowing any use by any party whatsoever, and offers few or no means or recourses to prevent a free rider situation or deal with proliferation of bad copies that misled end users.
Perhaps because of this flexibility, which facilitates large commercial users and vendors, the most successful applications of open source have been in consortium. These use other means such as trademarks to control bad copies and require specific performance guarantees from consortium members to assure re-integration of improvements. Accordingly they do not need potentially conflicting clauses in licenses.
The loose definition has led to a proliferation of licenses that can claim to be open source but which would not satisfy the share alike provision that free software and open content licenses require. A very common license, the Creative Commons CC-by-nc-sa, requires a commercial user to acquire a separate license for for-profit use. This is explicitly against the open source principles, as it discriminates against a type of use or user. However, the requirement imposed by free software to reliably redistribute derived works, does not violate these principles. Accordingly, free software and consortium licenses are a type of open source, but open content isn't insofar as it allows such restrictions. Similar arguments have often been made about the GFDL used in Wikipedia:itself.
