If there is one lesson to be learned from the Dojo Toolkit, it is “Be careful what you wish for!” When we first started Dojo, we had the modest goal of creating a JavaScript toolkit that would be useful and would prevent expert JavaScript developers from having to reinvent the wheel. With the buzz and excitement that would soon follow with the emergence of the term Ajax, we quickly found ourselves as the creators of a toolkit used by thousands and thousands of developers and millions of users in a very short time.

In the case of any project or company that grows much faster than expected, there are growing pains along the way. It has taken Dojo nearly 18 months to address and solve most of the issues caused by its rapid success: performance, comprehension, ease of use, and documentation. Open source projects are notoriously bad at both marketing and documentation, and Dojo was initially no exception to the rule. With each release from Dojo 0.9 to 1.1 and beyond, documentation and API viewing tools have improved significantly and are now something we’re proud to have rather than being a blemish to the project.

Above and beyond source code documentation, demos, and great examples is the need for great books. When learning something new, the most difficult things to learn are usually the questions you don’t know how to ask. The vernacular and philosophy of Dojo is very powerful and efficient but often leaves developers new to Dojo not knowing where to get started. Dojo in particular and Ajax in general also have the learning curve of basically needing to understand a wide range of technologies, from server-side programming languages to JavaScript, CSS, HTML, and the DOM, plus the browser quirks and inconsistencies across each. Toolkits such as Dojo go to great lengths to rescue developers from the most common and egregious of these issues, but developers creating something new will inevitably run into trouble along the way.

There are numerous opportunities for developers and users of Dojo to solve their problems and get up to speed, from reading this book to online community support, and the commercial support provided by companies such as SitePen.

Dojo has thrived and succeeded because of its transparent and open development process. All code is licensed under the AFL and BSD, licenses which are focused on adoption rather than control.

Contributions have been received from hundreds of individuals and from companies such as AOL, Google, IBM, Nexaweb, Renkoo, SitePen, Sun, WaveMaker, and many more. We have a strict but low-barrier contribution policy that requires all source code contributions to be made through a Contributor License Agreement, ensuring that usage of Dojo will not cause legal or IP headaches now or in the future.

And we innovate and experiment more than any other toolkit, introducing features in DojoX that are far ahead of other toolkits.

I first met James Harmon at a conference when he was giving a talk about Dojo. The great thing about James’ approach was that he did an amazing job of simplifying the message. Alex Russell and I have a tendency to beat people over the head with every feature and every possibility, whereas James was able to distill complex topics down to easy-to-follow concepts that help people quickly get up to speed with Dojo.

This book takes the same simple approach of clearly explaining how to create web applications and web sites with Dojo in a manner that should make it easy, even for developers who are not JavaScript experts, to quickly get up to speed and become effective with the Dojo Toolkit.

Dylan Schiemann CEO, SitePen Cofounder, Dojo Toolkit