Differences between Sun JDK and OpenJDK

Frans Thamura wrote:

> anyone have a list that compare Sun JDK with OpenJDK and also OpenJDK

> JRE with "Sun JRE

There is no OpenJDK JRE, specifically. The comparison that makes sense

is one between

Sun Java SE 6 JDK and the OpenJDK jdk6 project.


Differences are:


a) licenses:


OpenJDK jdk6 is Free Software, Sun's Java SE 6 JDK downloads are not, in

particular because

* they contain proprietary third party components (also known as

'encumbrancies'), that wouldn't be trivial to rip and replace in a

stable release series

* they contain Sun's own proprietary code that has not been / could not

be opened up so far


b) deployment code:


OpenJDK does not have a plugin or a webstart implementation.


The code Sun has in the deployment area has been largely rewritten for

Java SE 6 update 10, and the new code,

being a significant chunk of software, requires a new run through the

business decision making process on Sun's side.


Meanwhile, the IcedTea project augments the OpenJDK jdk6 project with

independent implementations

of the plugin and webstart, called gcjwebplugin and netx. Those

independent implementations have a different

set of strengths and weaknesses from Sun's implementations: they work on

64 bit Linux, for example, a platform

that hasn't been supported by Sun's own plugin yet. On the other hand,

gcjwebplugin currently lacks an

adequate Java-JavaScript integration that's required by some applets to

execute as well as expected.


c) bundled code:


Sun's Java SE 6 download comes with a lot of (third party) software

bundled in, for example

Java DB, Rhino, Visual VM, etc. OpenJDK jdk 6 project leaves such

software out as much as possible,

concentrating on the necessities required for a compatible

implementation of Java SE 6.


IcedTea augments OpenJDK jdk6 with Rhino, though there is still work to

be done on making the integration seamless.

There is also some initial work on integrating VisualVM into IcedTea.


d) encumbered code:


The Java SE 6 JDK still mostly contains the ~4 % of encumbered, i.e.

third party code that couldn't be licensed as

Free Software, and was replaced by open source implementations from the

community in OpenJDK 6.


cheers,

dalibor topic