What are swz files in Flash?

Question

When I build my project I get a bunch of swz files in the release/debug directory.

What are they?

They are quite big (1 mb in total) i just delete them, my swf works fine without them, so why are they there?

Solution

Adobe Flex Signed RSL file.

SWZ file is an Adobe Flex Signed RSL. Use Flex 3 runtime-shared-libraries (RSLs) to reduce the size of your flash applications and thereby reduce the time required to download the application. RSLs are just SWF files whose code is used as a shared library between different application SWF files. Signed RSLs (SWZ) are libraries that are signed by Adobe and may be stored in the Flash Player Cache, which can be accessed by applications from any domain.

Comments

[Gerhard Schlager]

When you delete those SWZ files and the Flash Player hasn't cached them yet it will try to download them from Adobe's servers. Just take a look at the build path of you application. Most of the Flex framework RSLs have fallback URLs set... That's why your application still works after deleting those files.

[Metafaniel]

Also this happens if you've got a TLF textfield in Flash. Sometimes this is a problem, creates those files you mention and generetes errors. You can change the textfield to 'Classic Text' to avoid these problems. If you've got many TLF textfields and you want to change them all to Classic Texts at once, just change the Flash Player version lower than 8 and all of them will be changed (then return the Flash Player version to the one you're using) and there you go!