jQuery is powerful javascript library. Almost all of our extensions are based on that library (Top Menu, Hot Image Slider, Hot Newsflash, Hot Joomla Gallery, Hot Joomla Carousel, Lightbox, Font resizer, and many more...). However, many Joomla extensions from other providers use other libraries (mooTools or prototype).
Using them together on a page will probably make conflicts. As a result, some or all of your extensions would not work.
However, we have found a solution. Our Joomla extensions use jQuery noConflict mode. Therefore, with our templates, beside our extensions, you can also use other extensions from other providers based on other libraries.