Add More Widgets To jQuery UI – Wijmo
If you're looking for alternative widgets, Wijmo, which is a set of 30 items, can be the one.
It has 2 versions where the "Open" version has ~15 free to use items and the "Complete" version, which is commercial (or free for GPL licenses apps), includes the full set.
Wijmo's "Open" version has many frequently used widgets like accordion, calendar, progress bar, slider, tabs, tooltip and more.
They make use of the jQuery UI CSS Framework and they are Themeroller-ready.
Compatibility: All Major Browsers