- 论坛徽章:
- 0
|
回复 1楼 jglxgz 的帖子
http://www.mysql.com/company/legal/licensing/faq.html
-------------------------------------------------------------------------------
What is MySQL's software licensing model?
MySQL uses a "dual licensing" business model. Under this model, users may choose to use MySQL products under the free software/open source GNU General Public License (commonly known as the "GPL") or under a commercial license.
With the GPL license, MySQL is available free of charge. Users may download the software for free and modify, integrate and distribute it. However, GPL users must abide by the rules of the GPL, which stipulate that if a MySQL-based application is redistributed, the complete source code for this application must also be open and available for redistribution.
MySQL AB offers a commercial license for organizations that do not want to release the source code for their application. Commercial license customers get a commercially supported product with a level of assurance from MySQL AB, without the requirement that their MySQL-based software must be "open sourced". MySQL is able to provide a commercial license because it has full ownership of the MySQL code.
MySQL's dual licensing increases freedom in two ways: first, it encourages the growth of free software by licensing MySQL under the GPL; second, it makes it possible to use our software in situations where the GPL is not applicable.
Why does MySQL offer two licenses?
MySQL's dual license model supports the company's mission: to make superior database software available and affordable to all.
The dual licensing creates a circle that sustains both innovation and growth: MySQL channels the revenue from this viable open source business model back into support for its open source user community that, in turn, supports MySQL AB's commercial business.
Today, MySQL AB has over 4 thousand paying customers who have chosen the commercial license and over 4 million who have chosen the open source GPL license. The dual licensing business model is a "win-win" for all parties:
* MySQL's open source community gets superior software for no cost;
* MySQL's commercial customers have the option of using reliable, community "battle tested" MySQL software for a relatively low cost;
* MySQL's business is healthy and viable, which also strengthens the open source movement.
How do I know which license to use?
The overall guiding business principle of MySQL's dual licensing is one of fair exchange or "Quid pro Quo" which means "something for something."
So if you use MySQL with GPL-licensed software (or a license that is GPL-compatible) we encourage you to use the GPL license. For all other users of MySQL, we recommend that you purchase a MySQL commercial license
For more complete guidelines on the GPL and commercial license from MySQL, please read our licensing overview or contact a MySQL representative online.
Do I get the same MySQL software under either license?
Yes. The MySQL product is essentially identical under either the GPL license or the commercial license. In some cases there are minor differences in the support libraries due to incompatibilities between the licenses of the libraries and MySQL.
How much does a commercial MySQL license cost?
As a result of its open source community and licensing model, MySQL AB is able to produce and offer its software at a much lower cost than what is typical in the industry. Current pricing for the server and other products can be found on our online store.
With a commercial license option, is MySQL still an "open source" company?
Yes, MySQL is still an open source company and is completely committed to the open source values and philosophy. We believe the open source model of development and distribution is the most efficient way to produce high-quality software. All MySQL software is offered under both open source and commercial license terms.
Are other companies using the dual licensing business model?
Yes, the dual licensing business model is becoming increasingly popular among open source companies as it paves the way for long-term financial viability. Other companies that offer dual licensing include Digium, OSAF, MandrakeSoft, Sleepycat Software, Technical Pursuit, Trolltech, and others.
Previously, the MySQL client libraries were licensed under the LGPL (the Lesser General Public License) and now they use the GPL (the General Public License). What prompted this change?
MySQL's goal is to provide all its software under a free software/open source license. The change from the LGPL to the GPL for the client libraries was made in 2001 during the development of MySQL 4.0 to help MySQL AB more easily differentiate between a proprietary user who should buy a commercial license and a free software user who should use the GPL license. Previously there were people that were misusing the GPL by distributing the MySQL server tightly coupled with their applications and claiming that the GPL doesn't affect them because the client libraries were free to use.
This change has allowed MySQL to support its dual licensing model by better identifying when someone is using MySQL software in a closed source fashion without commitment to the open source philosophy. While MySQL supports the open source ideals, we also believe in the notion of "Quid Pro Quo" or fair exchange. For developers building open source applications using MySQL, the change in the client licensing policy has no effect.
Based on feedback from our users, MySQL has introduced an exception that makes it possible to combine the MySQL client libraries with software that uses various Free and Open Source software ("FOSS") licenses. This is known as the FOSS License Exception.
What is the GPL License Exception for PHP?
Because PHP and MySQL use different incompatible open source licenses, we have created a special exception to encourage and promote the use of MySQL in the PHP community. MySQL AB gives permission to distribute derivative works that are formed with GPL-licensed MySQL software and with software licensed under version 3.0 of the PHP license. You must obey the GNU General Public License in all respects for all of the code used other than code licensed under version 3.0 of the PHP license.
There is also a more general exception which enables developers releasing software under other Free and Open Source software ("FOSS") licenses to include the MySQL client libraries. This is known as the FOSS License Exception.
What is the FOSS License Exception to the GPL?
The FOSS License Exception enables open source developers who are using Free and Open Source software ("FOSS") licenses other than the GPL to include the MySQL client libraries. Since some licenses are incompatible with the GPL this exception provides flexibility for open source developers. We want to support the open source community in their desire to use the MySQL client libraries in a broad range of open source projects.
Why has MySQL created the FOSS License Exception?
We created the FOSS License Exception to give developers greater flexibility in using MySQL with software that is under other Free and Open Source Software ("FOSS") licenses. Some open source licenses are not fully compatible with the GPL and so this exception makes it possible for developers to chose their preferred open source license and still have the ability to include the MySQL client libraries.
How did MySQL select the licenses for inclusion in the FOSS exception?
We have reviewed the most popular open source licenses to make sure that they can be used with the MySQL client libraries. If you are using a different open source license that follows the Open Source Definition by the Open Source Initiative and it is not on our list of approved licenses please contact us at license-feedback@mysql.com.
What is MySQL's policy on software patents?
We do not think that software patents are a useful way to protect software IP. Instead, we believe that copyright protection is sufficient. We have concluded that software patents are harmful to the software industry at large. This is why we support those who work for an abolishment of software patents. We also work with other companies and groups to build a joint defense against software patents. More information is available on our patent policy page.
How do I send MySQL AB comments on licensing or other issues?
The open source community is very important to MySQL and we want to hear all feedback! We have previously asked the community for specific feedback on licensing and will continue to do so to create an ongoing dialogue. You can send us your feedback using our feedback form. You can also fill out our survey on licensing and view the results.
Version 4.1, 12 March 2004 |
|