Things to consider when you're using jQuery
Before you investigate using jQuery further, there are a few things you should consider.
Browsers: Desktop, BlackBerry Device Software 5.0, and WebKit 6.0 and later
jQuery itself supports the most popular browsers. For information about jQuery support for each browser, visit the Browser Compatibility page on the jQuery site.
BlackBerry Browser support
Most computers now have multiple cores, at least 2.0 GHz of processing power, and enough RAM to accomodate the most inefficiently built applications. Smartphones have come a long way, but fall short of many computer benchmarks. The differences in hardware performance between BlackBerry smartphones running various BlackBerry Device Software versions alone can significantly affect application performance.
If you're porting an existing jQuery application from a desktop, even if all features are supported, you may still need to optimize for a platform that has fewer available resources. jQuery itself is not designed to be as light a framework as frameworks such as jqlite, zepto.js, jq.Mobi, or others, and thus will come with a slight overhead in performance, even in its minified form. On the latest BlackBerry smartphones and the BlackBerry PlayBook tablet, this is much less of an issue.
Which BlackBerry Device Software versions should I support?
This question comes down to you and the application you're working on. One of the primary considerations is who your target users are.
If you have a specific customer in mind, it might be best to take an inventory of the devices they use and the minimum requirements you have to support. If you only have to support newer BlackBerry devices, you can include more features in your application, and the hardware will be that much faster. For applications that are intended to support a broader audience, your decision may be based on the prevalent BlackBerry Device Software and BlackBerry devices in the market. BlackBerry Device Software 5.0 is still a strong target for consideration, consisting of 45% of the free BlackBerry App World downloads between November 1st, 2011 and February 1st, 2012.
For more information on the features and devices that each BlackBerry Device Software version supports, visit Choosing a Target Device OS.
However, there are times when you simply want to focus on development, and not spend too much time laying out, skinning, and tweaking various UI components.
You can use the jQuery UI library to simplify the process. This library provides you with many powerful components. However, this flexbility comes with the same considerations previously noted for using the jQuery framework in general. Specifically, there will be additional performance overhead as well as shrinking support on older platforms. There are options available that can help you minimize this overhead. jQuery Mobile can help you do this to an extent, but relies on the core jQuery framework and will be affected by some overhead as well.