I downloaded the Aptana_Studio_Setup_Linux.zip package, unpacked it and run ./AptanaStudio. It starts fine, but reports one problem:
The embedded browser widget
You will have to install XULRunner then edit the eclipse.ini.
After installing xulrunner, adding the following line in the eclipse.ini solved the problem of "No more handles" issue.
-Dorg.eclipse.swt.browser.XULRunnerPath=/opt/eclipse/xulrunner/
I am using eclipse 3.63 and ubuntu 12.04.