Prototype JS Library

Prototype

Pros
  • simple AJAX
  • Drag 'n Drop
  • Visual Effects (with Scriptaculous, Rico, etc...)
  • Event handling
  • Widgets
    • Autocomplete
    • Slider
    • Text Editor
  • Decent documentation (not centralized)
  • Widespread adoption
Cons
  • Not many widgets
  • Medium footprint
    • Prototype=54KB
    • Scriptaculous=28/23/32KB (depending on functionality)

Differentiators

(plus) Decent Documentation
(plus) Excellent community
(minus) Not many widgets

DEMO: http://script.aculo.us/

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