Flash Media Interactive Server and Flash Media Development Server provide plug-ins written in C++ that let you extend the functionality of the server.

Access plug-in 

Adds a layer of security before the server accepts connection requests from clients. The Access plug-in intercepts and examines each connection request (before the request reaches the server's script layer) to determine whether the server should accept or reject the request based on server statistics, such as the number of current connections. You can also code the Access plug-in to set permissions to server resources such as streams and shared objects.

Authorization plug-in 

Authorize client access to events that occur on the server. The Authorization plug-in authorizes connections to the server, playing of streams, and publishing of streams. It also maps logical URLs to physical locations. The Authorization plug-in can be configured to allocate the delivery of content for Flash Media Interactive Server clients according to geographic location, level of subscription, origin of the Flash Media Interactive Server stream, or time and duration of a user's access to specific streams.

File plug-in 

Provides an interface between the file I/O mechanism and the server. Developers can implement an alternative file I/O system in place of the server's default operating system-based file system. The File plug-in interface supports a fully asynchronous model for file operations, making it easier to implement network-based file I/O.

For more information, see Adobe Flash Media Interactive Server Plug-in Developer Guide and Adobe Flash Media Interactive Server Plug-in API Reference.