However, all is not rosy. The Aptana documentation’s guide to installing and running Aptana on Windows Vista recommends turning on XP compatibility mode, disabling desktop compositing, and always running it as Administrator. If you haven’t had an app turn off Aero Glass for you before, you’re in for a shock - it really sucks after you’ve gotten used to Glass. And running as Administrator isn’t that great an idea with a product as connected as Eclipse.
Fortunately, all is not lost. First, go to Sun and download the JavaSE 6 JRE (32-bit). It’s a huge upgrade from the Java 1.4.2 JVM that Aptana usually comes with, and it includes some major Vista compatibility features. Next, download and install Aptana minus the JRE from the Aptana downloads page. Already installed Aptana? Just go into the program directory and delete the “jre” folder. Now, make sure the Aptana shortcut doesn’t have any compatibility features checked. (Disclaimer: you might actually need to run as Administrator the first time you use Aptana, but certainly never again.) Start up Aptana, and everything should be glassy and smooth.
If Aptana complains that it can’t find the JRE, go into your Aptana program directory and open up aptana.ini. Add the line -vm='C:\Program Files (x86)\Java\jre1.6.0\bin\java.exe' to the top of the file, and save it. I had to do this mainly because I have both the 64-bit and 32-bit JREs installed, and while most Java apps work on the 64-bit JRE, Eclipse (and thus Aptana) doesn’t support 64-bit yet.
Update: Newer versions of Aptana come with Java 1.6, so this isn’t a problem anymore.