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For users running Java application or applets in the browser, what difference does it make running either Sun Java or OpenJDK?


Oracle will be retiring the DLJ, and basing the proprietary implementation on OpenJDK. Can we expect similar experience in running Java apps using either OpenJDK or Oracle JDK?

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I believe that's about graphics performance (said to be lower in OpenJDK, Eclipse is said to be faster with Sun JDK), lack (or a replacement of a kind, meaning non-usual, which will raise compatibility issues) of patented (like some graphics, encryption, compression etc algos), 3-rd-party-copyrighted and restricted (like strong encryption) features implementation in OpenJDK. And I will definitely celebrate if upcoming Linux port of Java FX 2.0 will work properly with OpenJDK and be available through the repos. – Ivan Nov 3 '11 at 20:58

Suns JDK is much faster for many applications using advanced graphic capabilities (2d and 3d), to the point that some applications are actually not usable using openjdk. See eg:

If I download the .tar.gz version of SweetHome3D (including the Sun JRE 1.6.0_20), the performance is excellent : moving inside the 3D view is smooth and easy to use If I launch it with Java Web Start (the one that comes with icedtea6-plugin package, that launches it under OpenJDK version 6b18-1.8-4ubuntu3), the 3D view is extremely slow, and unuseable.,1658;jsessionid=29F65F93678EF71A067DFEEDDC298B14

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There is no difference except for those applications which don't work properly with the OpenJDK.

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Yes, applications not working with OpenJDK is the difference. Why does it not work, what's the difference? – Oxwivi Sep 15 '11 at 16:36
OpenJDK is a re-implementation of Sun's JDK, as any re-implementation of such a large software there are differences, either because of bugs or different decisions regarding certain behaviors. I don't have a link for those bugs, I know they are bring worked, but at this time it is known that are many websites wick work with sun's jdk and not with the openjdk. – João Pinto Sep 15 '11 at 17:34
So the obvious next question is: is one better than the other? And since Sun's JDK is being dropped from the repositories (according to a number of websites, e.g. here:, leaving the OpenJDK available, is it worth it to get and install the Sun JDK? – Kelley Sep 15 '11 at 19:58
"Better" is a subjective term, from a compatibility standpoint Sun's JDK is better, a large number of applications are developed and tested only with Sun's JDK, however if your users can work with openjdk it's always preferable to use the open source version. – João Pinto Sep 16 '11 at 7:48
Yes, I've heard of the retirement of DLJ as well. Since Oracle Java is now going to be based on OpenJDK, how will they differ? – Oxwivi Sep 16 '11 at 12:51

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