A collection of extensions from the [Rails-Spinoffs list](http://lists.rubyonrails.org/mailman/listinfo/rails-spinoffs) this will be a growing personal resource, send in more if you know of them.

sam.google

* [Rico](http://openrico.org/rico/demos.page?demo=rico_drag_and_drop_custom_draggable)
* [Event Selectors](http://encytemedia.com/event-selectors/)
* [Script Aculo](http://script.aculo.us/)
* [Window Class http://prototype-window.xilinus.com/](http://prototype-window.xilinus.com/)
* [collection of widgets](http://tetlaw.id.au/view/tags/query/tag/experiments/)
* [Color Picker](http://www.knallgrau.at/code/colorpicker/demo)
* [Tool Tips](http://boygeni.us/tooltips/)
* [Plotr](http://www.solutoire.com/plotr) 3/19/07
* [Kalander](http://www.xutopia.com/kalander/) 3/19/07
* [LowPro](http://www.danwebb.net/2006/9/3/low-pro-unobtrusive-scripting-for-prototype) – unobtrusive scripting for prototype 3/19/07

From M. Peters

* [Spinelz](http://script.spinelz.org/) (lots of widgets)
* [Notify.js](http://thinkof.net/projects/js/notify/notify.html) (modal popup)
* [Polygons](http://polygons.mdaines.com/) (really neat, but I haven’t use it yet)
* [Tabs](http://net4visions.com/dev/tabs/tabs.html)
* [DataGrid](http://development.finetooth.com/?p=13)
* [Multi File Upload](http://mlmlml.yaekumo.com/MultiFileUpload/)
* [You can see more here](http://del.icio.us/mpeters/prototype+library)

From (Particle Tree)[http://particletree.com/notebook/extending-prototype/] and Ryan Cambell

* [Prototype.Extension](http://livepipe.net/projects/prototype_extensions/)