[reboog711]

The file format spec is available:

https://www.adobe.com/devnet/swf.html

I know it isn't the same as "Open Sourcing" the Flash Player code, but it is how many programs--Camtasia as one example--have/had an "export to Flash" option.

[giancarlostoro]

There's still the Shockwave one (Macromedia Shockwave, not "Shockwave" Flash) that's still undocumented by Adobe.