Balsamiq Mockups allows software designers and developers build great software by letting them easily sketch out their ideas, then quickly collaborate and iterate over them. Mockups offers the same speed and rough feel as sketching with a pencil, but with the advantage of the digital medium: enlarging containers is just a drag operation.
jQuery is a cross-platform JavaScript library designed to simplify the client-side scripting of HTML. It is free, open-source software using the permissive MIT License. Web analysis indicates that it is the most widely deployed JavaScript library by a large margin.