1.3.0 — Jan. 11, 2012 Removed AMD (RequireJS) support from Underscore. If you'd like to use Underscore with RequireJS, you can load it as a normal script, wrap or patch your copy, or download a forked version.
Why have they done it? Does anyone know? Because they added it only few month ago (in October), and AMD (Asynchronous Module Definition) is said to be far superior to CommonJS modules.
Update: As of December 2013, this has been supported again.
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