why browsers don't put important javascript library like jquery or extjs in their package? [closed]

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why web browsers don't put important javascript library like jquery or extjs in their package? with this work sites loading time be low.

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There's a CDN for jQuery. Using it assures, jQuery will be in browser cache even if someone visits certain site first time.

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How do you propose that a browser differentiate between a reference to /libs/jQuery.js and one to /libs/SomeApplication/someFeature/jQuery.js ?

Especially if

• the first one is an old version where you integrated one or two bugfixes
• and the other one just the compatibility layer for jQuery in SomeApplication (so not even anything related to jQuery own source code)