I finally found a little project I wanted to do using Adobe Air and after some searching I found out you can use Linux to develop Air applications. At first I thought I would have to use Flex Builder which is still in alpha for Linux but it turns out there is a better option from Aptana.
I started by downloading and installing the latest version of the Air runtime. Next I grabbed the Air SDK, the SDK doesn't come with the plugin so it is something you have to get directly from the Air developers site. After getting the SDK unpacked I installed the latest Aptana core release. Once the core is installed there is a big plugin button on the startup screen that currently has Air listed.
The install went smoothly except for a few issues. The first one I ran into was very noticeable since it kept any dialog buttons from working when they were clicked although they did work when I clicked them and then hit enter or navigated to them with the keyboard. Luckily someone has already figured out that there is an issue with Eclipse and GTK+ that is the cause (even though the post is for Ubuntu the same problem and solution worked for me on Fedora). The fix is to set the GDK_NATIVE_WINDOWS variable before running the Aptana binary:
The next thing I noticed was the application.xml descriptor that Aptana created didn't generate correctly. It needs to start with the correct xmlns or the following error will be thrown on run: "invalid application descriptor: descriptor version does not match runtime version". To fix this check the version of the Air SDK by running the following command:
adt version "126.96.36.19920"
For the version of the Air SDK I downloaded the correct xmlns was http://ns.adobe.com/air/application/1.5 so I needed the following application tag:
Once I had that working I was able to compile and execute a demo application. I was also able to create an Air application package from within Aptana using File > Export > Adobe AIR > Adobe AIR Package. Before creating the Air package I had to create a signing certificate. Creating the certificate can be done within Aptana too but because I had not yet fixed the above button issue I created a cert on the command line with the Air SDK and then imported it. To create the Air signing certificate from the command line I used the adt command from the SDK:
adt -certificate -cn SelfSigned 1024-RSA sampleCert.pfx samplePassword
Remember the password that gets used to generate the certificate because it will have to be used before a package is signed.
Finally Adobe has a lot of information on developing Air applications on their Air devnet site. The Air ajax section is especially important.