Hi nishnatha, a few pointers:
Most libraries are written to bind into the Browser so may require tweeking to work within Test Complete.
Libraries that are DOM/GUI specific are not of much use as Test complete has no Browser or DOM objects.
The Wikipedia page somewhat bizarrely fails to mention any json libraries, such as json2.js, which can be very useful for testing Web.
In order to use a JavaScript library, change the extension from js to sj and add to your project as an Existing Item.
Most libraries utilise the JavaScript Closure Module pattern which can cause issues with Exception handling. I recommend writing Script Unit level functions in the Script Unit that contains the JavaScript library that access the functions, wrapped in try catch blocks, of the JavaScript library. It is these functions that are then used to utilise the JavaScript library instead of calling the JavaScript library directly.
Regards,
Phil Baird