"We have published the kendo-ui-core repository to GitHub and are accepting contributions from the community," said John Bristowe, a principal developer advocate for Telerik, in a blog post. "A pre-built version is also available for download. Finally, our commercial version of Kendo UI, Kendo UI Complete has been renamed to Kendo UI Professional."
Telerik officials said the company released this package to give back to the developer community for its long-time support for Telerik and its products. The package will be released under the permissive Apache 2.0 license, allowing developers to use the library in both commercial and non-commercial projects and also to contribute to the library itself.
The Kendo UI Core open source offering includes 38 UI widgets, including all of Kendo UI Mobile, and all of the core framework features, such as templates, data binding, and input validation; access to thousands of tests and best practices; tight integrations with Bootstrap and UI widgets ready for use with popular libraries like AngularJS; and public availability via a GitHub repository and Telerik.com.
Kendo UI Core includes 24 of the UI widgets currently in Kendo UI Web, all of the widgets and features formerly available under Kendo UI Mobile, and all of the core framework features of Kendo UI. However, with Kendo UI, you don't have to adopt the entire framework to use just one widget.
In a statement, Brad Green, engineering director for AngularJS, said he is "impressed with the beauty and completeness of Telerik Kendo UI components" and is "ecstatic that it has gone the open source route to enrich the world's development community."
Kendo UI Core offers the community a license compatible with a broader variety of project types, the company said. Contributions to the evolution of the technology are encouraged, as is its use in commercial and non-commercial projects. Telerik plans to ship Kendo UI Core as part of other product packages like Kendo UI Professional, Telerik UI for ASP.NET MVC, and more. Telerik also plans to remain active in the development and advancement of Kendo UI Core via new widgets, fixes and feature enhancements.
Indeed, in a blog post, Holland said there are 12 full time engineers continuing to work on Kendo UI Core as an open-source project. "We will continue to do three major releases a year with a minor one in between each major. That's 6 releases a year. The only difference is that now all of the development on Core will be done in the open…"
Holland explained that the software industry has had a rather bad track record of mainly open sourcing software that has been given up on. However, "That's the old meaning of open source," he noted. "The new meaning of open source is projects that are active and aggressively maintained and released all in the open. Kendo UI is being open sourced under the new meaning; the same way that jQuery is open source, Angular is open source and Bootstrap is open source."
The decision to use the Apache 2 license was to enable developers to use the core tools more broadly. Since its inception, Telerik has published a version of Kendo UI Web via a GPLv3 license.
"Many of our developers were glad to have this option for using Kendo UI, but because the GPL is a restrictive license (i.e. can only be used for non-commercial projects), its value to the overall developer community has been limited," Bristowe said. "The GPL license also prevented us from being able to accept community contributions for Kendo UI Web from interested customers. With Kendo UI Core, we're chosen to adopt a more liberal BSD-style license; Apache License, version 2.0 and retire the GPL version of Kendo UI Web. This allows offer developers with a license that's compatible with a broader variety of project types…"
Meanwhile, some Kendo UI widgets, such as the data grid and data visualization tools, will remain exclusively available via commercial Kendo UI distributions. Developers needing extra power can easily purchase these commercial widgets, along with Telerik's support, to enhance a project started with Kendo UI Core.