Prototype.js sounds very interesting. I'm about to start writing a pretty hefty JS lib of my own, and I'm wondering if any of you guys use it regularly and your opinions? To you find you can get more work done with the added constructs prototype provides, rather than just straight JS and maybe jQ?
Do not write your own library from scratch. It sounds a whole lot easier than it is since most of the work in writing the library isn't the actual code writing but rather getting it tested and debugged in all the variants of all the browsers. Use a library.<p>As for which library, they provide mostly the same functionalty at the bottom but differ in the high level feature set and how they're organized. My take:<p>* jQuery - Most popular, best for 'ajax sprinkes' apps but less great for full-on applications<p>* prototype - Prototype hacking outside of ES5 feature backfilling is evil<p>* mootools - The community cares a lot about their visuals but I got burned with a number of bugs caused by them taking shortcuts for size. This was 4 years ago so the kinks are probably worked out, but there are other options so meh.<p>* yui3 - My favorite. Built around a selector api, fine grained module system, custom event based, and the UI layer is very much about progressive enhancement. The downside is that there's not a lot of community support.<p>* sproutcore - the absolute best data layer, UI layer wants to own the page<p>* dojo/yui2/closure - I don't like these because I think they're too heavy or too much like java<p>My specific problem with jQuery is that every app over 1k lines or so tends to go spaghetti. The module/event systems in dojo and yui and the data binding in sproutcore guides you to a more modular system which makes for a more pleasant application building experience. There isn't really a technical reason you couldn't do it with jQuery but I've never run across an elegant, modular jQuery codebase. If anybody has one, I'd love to see how it's structured.
We use it at both the day job and in my business. It is <i>clearly</i> better than nothing. If I were starting from zero today, I'd take a very close look at JQuery, as I think the web development community is rapidly standardizing on JQuery, which means pre-made things that I want to incorporate are disproportionately written in JQuery. However, I have never been totally unable to find a Prototype moral equivalent for the types of controls I have wanted. (e.g. a color picker)<p>Your mileage may vary, by the way, but I think it cuts about 90% of the pain out of AJAX development... leaving 90% to go.
I think over last years jQuery won popularity contest with prototype.js and other libs. It's very handy and consistent. Lots of plugins exist that provide additional functions.
MooTools (<a href="http://mootools.net" rel="nofollow">http://mootools.net</a>) contains all the capabilities of jQuery and Prototype.js, together with a very impressive class system which allows for better modularity in your code. It has a very supportive community and is being constantly developed. You might also want to read Aaron Newton's long post comparing jQuery to MooTools: <a href="http://jqueryvsmootools.com/" rel="nofollow">http://jqueryvsmootools.com/</a><p>That being said, you'll find much more people fluent in jQuery or Prototype.js than in MooTools.
We use both jQuery and Prototype together in our app. I love jQuery and would love to use it exclusively, but our architecture was build around Prototype's class extension capabilities, which I have to say are pretty damn convenient. Beyond the ability to make JS much more easily handle inheritance, I haven't found much benefit from it over jQuery.<p>I'm also specifically annoyed at how it tries to modify the HTMLElement prototype, since that's not allowed in IE < 8, and caused some weird bugs for me (sure, it should be mutable everywhere, but let's be realistic: IE < 8 has a huge market share, and should have code consistency. After all, that's what JS frameworks are for, amongst other things).
If you haven't committed to a Javascript library then I'd take a look at jQuery. Every library has it's pros and cons but you'll likely find more support for jQuery than any of the others.<p>I used to use prototype.js and once I used jQuery I never looked back.<p>Props to prototype.js though as it was one of the first standard libs that did a really good job abstracting away the crappy parts of JS (browser deps).
Depends on what are you going to do - I created quite big apps in both jQuery and Prototype.<p>Whatever you want to do - you can do in both - it all depends on the size. I find Prototype better for big projects where you can use it's class system. It feels like Ruby as well.<p>jQuery on the other hand is small and gets the job done, but without a plan on how to structure your code things can get really messy.
Love prototype, works around browser issues, is fast and if you really need special effects, get the script.aculo.us companion lib. Other bonuses, it enumerates, and navigating the dom is easy. If you need updating via ajax there is a lean function or full on functions and callbacks it can do that too.