From Gnash Project Wiki
The BuildMatrix page tracks the architectures and operating systems on which Gnash had been successfully tested, and also serves as a temporary compatibility list. The SWF_compatibility page tracks SWF issues (differences between versions, state of support by Gnash).
Example Flash Files
The files listed on these pages can be used to test the Gnash player.
LoadingFLV - examples of sites loading FLV files at runtime
External Web Sites
Specific, external web sites with which the Gnash player should be compatible.
These pages list hardware or other requirements for Gnash to run successfully.
These pages include tips that might help in troubleshooting Gnash.
Notes that refer to test cases and other testing information specific to the project are listed on the following pages:
MovieTester - a Gnash class that is used to automate testing with arbitrary SWF inputs.