A computing device programmed with an extensible framework that accepts one or more mark-up language parsers and/or generators, each implemented as plug-ins to the framework, with different plug-ins enabling different kinds of mark up languages to be handled by the device. In this way, the client is no longer tied to a single kind of parser or generator; it can operate with any different kind of parser compatible with the intermediary layer, yet it remains far simpler that prior art clients that are hard-coded to operate directly with several different kinds of parsers and generators.