Create fluid and interactive gradients animations with this small (< 10 kB) js library.
prettyPhoto is a jQuery based lightbox clone. Not only does it support images, it also add support for videos, flash, YouTube, iFrames. It’s a full blown media lightbox. The setup is easy and quick, plus the script is compatible in every major browser.
A flexible neural network library
Cool jQuery datepicker
Accessible rating forms with cute animations on top.
A library for explaining things in HTML.
A customizable CSS-only vertical timeline
A simple sketchpad library
Growl-style alerts and messages for your app. #hubspot-open-source
A positioning engine to make overlays, tooltips and dropdowns better #hubspot-open-source