NOTE: This no longer appears to be the case (August, 2009). I'm keeping this page for historical reference.
Typically, when launching 64bit Eclipse on 64bit Ubuntu, it will crash. The problem is Sun's JVM.
http://www-128.ibm.com/developerworks/java/jdk/linux/download.html
You will need to register, but it is free.
Java SE Version 6" "64-bit AMD/Opteron/EM64T"
I got the tar.gz version and extracted it to
/opt/eclipse-3.4.1-x64
I created an eclipse_ibm script like so:
#!/bin/bash PATH=/opt/ibm-java-x86_64-60/jre/bin:$PATH /opt/eclipse-3.4.1-x64/eclipse
To install Aptana, you must download the zip file and install the plugin from there. Direct over the web install will fail.