1. In a computer system, an improved method for developing a Web application, the method comprising: providing a Web application development framework, said framework including an abstract command tag that predefines at least some generic Web application activities; specifying at least one custom action that is desired to be performed by a Web application; creating an object-oriented programming language (OOPL) class that extends the abstract command tag for providing execution logic for said at least one custom action, in addition to pre-existing logic that supports said at least some generic Web application activities, thereby creating a corresponding customized command tag that is capable of being embedded within a Web page; mapping a customized name of the customized command tag in a tag library descriptor file to the custom action; embedding the customized command tag with the customized name in a Web page of the Web application; and upon execution of the Web application including the embedded customized command tag in a Web page, invoking the customized command tag for conditionally executing said specified at least one custom action based on run-time conditions of the Web application and run-time values for one or more attributes included in the customized command tag.