Don't fall in love with frameworks

The javascript world is on fire!
You've got tens of frameworks, all made to enable making javascript and web development easy.
angular, backbone, less, _, GWT, wicket, the old and established extjs, prototype, yui, and jquery (To name a few) have become common names among developers.

Some frameworks are meant to make your life easier with dom traversing and manipulation and encapsulate javascript features (jQuery, prototype), some add UI functionality (extjs, yui), while others offer full application frameworks.

However, these frameworks come with a price.

Once you bind your application to a framework, it's very hard to get rid of it. It's very hard to change parts of your application, once your web application is fitted with the paradigm of a framework.
Binding UI to model is another problem - Some of these frameworks bind data to UI components.

While this makes your initial development easy, once your application surpasses some volume and features, programmers tend to break this model (Something which is quite easy with javascript).

Binding is also very hard to debug - Sometimes you'll get an impossible to understand and follow call stack, especially with frameworks which bind model to UI components via events.

Another reason is performance: If all you want is a 3 page application which loads json objects, parses them and presents them on screen, using a full fledged MVP framework is a little bit of an overhead.

... And now, for the worst part.
You've written a nice widget/ control/ viewer/ whatever.
Now someone wants that object in his legacy system.
It's very hard to integrate binded code.
You tell him you can't.
He asks you why did you use the framework, if your code isn't recyclable.
You say 'it is, but you need to rewrite your whole client'.
CTO approaches you with angry eyes.

The rest - You know.

So next time you consider using a flashy, 'easy' to use framework, please ask yourself these questions:
- Will you need to reuse this code somewhere else?
- How much overhead will the framework add? Is it really necessary?
- How intrusive is that framework, in case you want to replace it?
- How much time would it take your team to develop the features you need from the framework? Don't add a full fledged framework for the sake of a neat button!
- How cryptic is the code? (Angular.js is a good example - Great framework, but you need to go all the way with it in order for you to enjoy its advantages.)
- How easy is it to debug? I know some of them are really, really hard.
And, finally:
In 6 months from now, will it bring value to your system, or will you need a month of knowledge transfer just to get someone new to write features into your app.

Be responsible - Use new technology that brings value, not heartbreak...