32-bit or 64-bit

The basic idea is that to use a 64-bit version of Eclipse, you must have a 64-bit JVM and an operating system that will support 64-bit applications. When in doubt, choose the 32-bit version of Eclipse, it is more likely to work than the 64-bit version.

32-bit or 64-bit?

Under Mac OS X 10.7, the default JVM is 1.6, which is 64-bit.

Under Mac OS X 10.5 and 10.6, the default JVM is 1.6, which is 64-bit. However, Java 1.6.0_20 does not work well. The issue is that the following stack trace appears:

      2010-10-10 11:50:02.263 java[7823:613] java.lang.NullPointerException
      at apple.awt.CToolkit.postEvent(CToolkit.java:1086)
      at apple.awt.EventFactoryProxy.forwardEvent(EventFactoryProxy.java:53)

The bug happens when running from Eclipse or from the command line. The bug requires UI interactions such as mouse movement or clicking. The bug is probably a threading bug and may only show up on multi-core machines. The downside is that when the bug occurs, the debugging session in Eclipse may become non-responsive.

For further information, see: http://lists.apple.com/archives/java-dev/2010/May/msg00140.html.
So, at this time, we are recommending the 32-bit version with Java 1.5 and Mac OS X 10.5. Below are instructions for using the 32-bit version of Eclipse. These instructions are for Mac OS X 10.5 only. Mac OS X 10.6 and 10.7 should use the 64-bit version of Eclipse
Download eclipse-rcp-indigo-macosx-cocoa.tar.gz uncompress it and move eclipse/ into /Applications, which will create /Applications/eclipse/Eclipse.app.
Firefox Mac OS X Details for 32-bit under Mac OS 10.5:

  1. Firefox will download the file into a directory, which may be /Downloads
  2. Double click on eclipse-rcp-indigo-macosx-cocoa.tar.gz which will create the eclipse directory.
  3. Drag the eclipse directory to your Applications directory.

The next step on the Mac is to force Eclipse to use Java 1.5 by editing eclipse.ini.
  1. In the Finder, go to /Applications/eclipse, find the Eclipse executable and right click (Control + click) and choose "Show Package Contents".
  2. Browse to Contents/MacOS and double click on eclipse.ini, which will open up the file in TextEdit
  3. Edit the file and insert 
    	  -vm /System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/bin/java
  4. Save the file and exit TextEdit.

For details about eclipse.ini, see http://wiki.eclipse.org/Eclipse.ini
When you start up Eclipse, if you want to verify which version of Java you are running Eclipse | About Eclipse | Installation Details | Configuration.
For Java 1.5, the java.class.version property should be 49.0.
For a 64-bit JVM, the java.vm.name property might have the string 64 in it.

Return to the Installing Eclipse page.