Chapter 17. Modules and Runtime Shared Libraries

When building Rich Internet Applications, eventually you will have to consider file sizes and download times. The Flex Framework offers several alternatives for separating application code into separate SWF files to enrich the user experience.

Runtime shared libraries (RSLs) are files that can be downloaded and cached on a client. A downloaded RSL persists on the client, and multiple applications can access assets from that cached RSL. Applications can load two types of RSLs: unsigned and signed. Unsigned RSLs, such as standard and cross-domain SWF files, are stored in the browser cache. Signed RSLs, which are libraries that have been signed by Adobe and have the .swz extension, are stored within the Flash Player cache.