About Licence of Flash media playback

I'm not too sure what you're asking, but I will attempt to assist.

If you asking about the Adobe Flash Media Playback, it is not Open Source, but  is free and is hosted on Adobe's server clusters. If you want the Open Source Media Framework (OSMF) version, you need Strobe Media Playback, which can be found here.

If you're referring to the Adobe Flash Media Server licensing, it is not Open Source, and a license for whichever version you need must be purchased from an authorized Adobe Reseller. The trial version is known as the Adobe Flash Media Development Server and has no time limit for installation, but there are limitations on available features. A list of features in all FMS products and limitations within the Adobe Flash Media Development Server can be found in the feature matrix in the FMS 4.5 White Paper, located here.

Lastly, it is most important to note that your post is in the wrong forum. For future reference, if you have FMS related questions, they should be posted here:

http://www.adobe.com/go/fms_usergroup/