Java is not required and is not preinstalled in OS X. There are 2 sides to Java. The web browser plug-in/extension – this is the BAD form, as it has been nothing but security holes.
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Mac OS X 10.6 and below: Apple’s Java comes pre-installed with your Mac OS . Mac OS X 10.7 (Lion) and above: Java is not pre-installed with Mac OS X versions 10.7 and above. To get the latest Java from Oracle, you will need Mac OS X 10.7. 3 and above.
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