ZK Licensing FAQ

What open source license does ZK use?


ZK CE is freely available under the open source LGPL license. It's free for open source as well as commercial development and deployment.

ZK and supplement products have multiple licensing options available to meet different needs. For more information, please visit the license page.


Why did you change your open source license from GPL to LGPL?


To extend our reach beyond what a GPL-licensed framework can achieve, ZK 5 and later CE are now moving to LGPL offering more freedom and allowing ZK to be integrated with more frameworks under different licensing models.

Now, with the LGPL-licensed ZK 5 and later CE, you are free to use, develop and deploy your ZK CE powered application/framework, regardless of whether it is open source, proprietary, or commercial.


Will ZK CE take a backseat to ZK PE and ZK EE?


No. We want ZK to become the de facto standard within enterprise Ajax. We see ZK CE as the most important factor in achieving this goal, thus are making significant effort to improve the product and achieve our vision. To date we have already added more than 50 features to ZK 5 CE with more scheduled in the future.

To realize our vision we need to hire first-rate engineers and evangelists to further ZK which would not be possible without continuing our dual licensing policy for PE and EE. Hence, a balance must be maintained to create a healthy ecosystem and further ZK's leadership in enterprise Ajax technology.


Can I use ZK 5 and later for free? Can I upgrade my ZK 3 GPL-compatible project to ZK 5 and later?


ZK CE is licensed under the LGPL which offers the community the ability to freely use ZK CE wherever they please, including open source or commercial applications.

For people who count on ZK 3 PE and EE we have continued our support for the open source community by providing any GPL-compatible or open source project the ability to make use of ZK 5 and later PE and EE under ZK Open Source License free of charge.

If your project is not GPL compatible or open source but you want to make use of PE and EE's benefits then we have other options. We strongly believe in looking after and helping people who have helped us take ZK to its current levels. Therefore, we have special discounts on our products for community members who have collaborated with us in the past.

If you are new and want to leverage PE and EE but have a tight budget you can share works with the community such as small talks, blog posts and use cases in exchange for a discount. If you are interested in this please contact us.


Why don't you just make money from support?


Making money through support conflicts with our aim of making ZK the most intuitive and productive framework on the market. Our vision is to create a framework where minimal support is needed. Therefore, making money through support is not a viable option for us.
Give us Feedback!
How would you improve the ZK learning experience?