jQuery is by far the most widely used library for JavaScript. It is used on more than 50% of websites. Many frameworks, such as Backbone and Twitter’s Bootstrap, are built on top of jQuery. Being able to extend and write plugins for jQuery can not only save lots of time, but also makes code much cleaner and easier to maintain.

believe the power of jQuery is highly underutilized. Most developers will take advantage of its shortcuts and CSS selectors, but most of the time they fail to take advantage of much else. Being able to extend jQuery, whether by adding your own functions, CSS selectors or full-blown plugins, makes you a much stronger and smarter developer.

Reusability is key in reducing bugs and coding quickly. The more I use a piece of code, the more confident and familiar I become with it, which in turn significantly speeds up my development time.

In my experience, requirements change quite often, or new situations will arise that weren’t anticipated at the start of the project. If the situation can be addressed with a plugin, I just whip open the standalone plugin page, make the updates and pop the new plugin back in. Because the plugin is self-contained, it’s easy to recreate the problem, fix it, and get it back into the codebase.

Ultimately, I try to think of my application’s main codebase as just stringing together various components and code from many sources. It just controls logic and flow. The real nitty-gritty is handled behind the scenes. This is why frameworks like Backbone are so important — they hide a lot of the details in the background and allow you to just focus on the flow and control of your application.

A good standalone plugin can also make you a fair amount of money. Many developers make a decent living by simply maintaining and updating one or two crucial plugins that are far better than anything available for free.