According to a report, Ben Forta has said:
"The project is currently on hold. There is not enough requisition for the product to continue its development"
This is very bad news for anyone who uses Linux to produce Flex content, as the existing build on Adobe Labs is incomplete, even compared to the existing Flex Builder 3 product. It's also not been updated very much, and certainly not recently (there are funny manual steps required to get the latest Flex SDK and AIR working with it, for instance).
I dread to think how much further behind it will be allowed to drift if this report is true, and so I've logged a formal bug with Adobe.
And that's what I'd like your help with - if you believe Builder should be as cross platform as other Adobe tools, like Flex and AIR, vote on this bug : http://bugs.adobe.com/jira/browse/FB-19053
Adobe say they listen to bug reports, and the number of votes is important. I can't vote, I logged the bug - so, if you currently use Flex Builder on Linux register your support for this great product so we don't see it die.
There shouldn't be any real reason why this can't happen. It's all just Eclipse and Java. Adobe used to say they needed a special version of the player called authplay on Linux. But as of Reader 9.1, Linux is using that to run SWFs inside PDFs.
The only thing left that I can think of is just the QA overhead of having a larger test matrix... and we'd pay for Builder, so that should cover that.