JavaScript Libraries in particular have grown immensely in popularity, and the article continues to be a great resource. However, it was apparent from how the Web development community responded, that there was a single missing component. Designers and developers wanted an at-a-glance comparison chart. I considered how to go about researching and writing such a comparison, and shortly thereafter, I was contacted by Cody Lindley. He let me know that he'd been working on such a chart. Here is that chart.

		DOM Assistant 2.5	YUI 2.4.1	jQuery 1.2	Dojo 1.0	Prototype 1.6	EXT 2.0	Mootools 1.11
1	Official (complete!) documentation (API found on domain)
2	Official off-line documentation (off-line API found on domain, included in download, and managed by Dev. team)
3	Real code, with working live examples included in the API (not just demo's/tutorials out side of the API)
4	An official manual/book, not an API, not tutorials, but a manual/book online or hardcopy
5	Official real world demos included in download
6	Modular by design (one file by design, or multiple)
7	File size (KB) not minified, obfuscated, or gzip (? = depends upon what you include)	41.4	29 - ?	77.4	219 - ?	121	29 - ?	9k - ?
8	Official minified version (removing just comments and spaces)		6 - ?	44.6			7 - ?
9	Official packed/obfuscated version	21		26.2	50 - ?
10	Official hosted minified version with gzip (free, unlimited)
11	Official widgets/UI toolkit
12	SVN/CVS access
13	Unit tested
14	Public unit testing
15	Open development
16	100% Funded development (paid, full-time developers, only focus)
17	Official forum
18	Official Mailing list
19	Commercial support and training
		DOM Assistant	YUI 2.4.1	jQuery 1.2	Dojo 1.0	Prototype 1.6	EXT 2.0	Mootools 1.11
20	Official plug-in architecture (was the base code designed and documented (documentation key) to facilitate open plug-in development by the community) Similar to modular, but with a different intent.
21	License type	GNU	BSD	GPL / MIT	AFL / BSD	MIT	LGPL	MIT
22	Free for Commercial use
	Official support for Safari 1.3+
	Official support for Safari 2+
	Official suppor for Safari 3+
	Official support for Opera 8+ Mac/Win
	Official support for Opera 9+ Mac/Win
	Official support for Firefox Mac/Win 1.5+
	Official support for Firefox Mac/Win 2.0+
	Official support for IE 7
	Official support for IE 6
	Official support for IE 5.5
	Official support for IE 5.0

There are several factors to consider when compiling the necessary information for this comparison. The first, and most important, is terminology. Even though there are numerous features and functionalities for each JavaScript library that are similar, they do not always fit neatly into predetermined headings. It remains imperative that each library feature be weighted while keeping this in mind, and when appropriate, read the full description that accompanies each heading. This is a fantastic starting point for your own research and analysis.

Although the groundwork has been laid, another factor to consider is that there is still the effort to maintain an accurate comparison. Remember, this is a living document, and you should use the chart whenever you begin a new project that requires a library. After listening to developers who have used these libraries, we intend to make updates, modifications, and maybe even a major overhaul. The intent is to facilitate discussion, and to be the primary (most accurate) resource for determining which framework is right for you, and right for the task you need to accomplish.

Before the initial release, several of the programmers who are responsible for the creation of these libraries were contacted, and their opinions will always be taken into consideration. This helps us to maintain a balanced, unbiased opinion. The number of options available to developers today can be daunting, and helping you to choose the right tool should be done without any preconceived notions on our part. We will not always be able to guarantee that each of the creators of these libraries agree on our comparison criteria, but we will always take the steps necessary to listen and cooperate.

The final consideration is determining which libraries to include for comparison. This is a little easier to determine, since the decision is driven from a set of closed questions. Is the library licensed under an open-source license? Is there API documentation, and how often is it updated? How mature is the library, and how often are updates released? Is this a core library, or is it an extension/add-on/plugin to an existing library? These are not the only questions to ask, but they are a few that can help with the process of elimination.