Web applications service a gamut of users with a mix of static and dynamic resources: requests come from different devices running different Web agents (typically, Web browsers) with different capabilities. In a majority of such interactions, services are embedded in an HTML page and displayed on a Web browser. Consequently, Web application development has been tightly coupled with the platforms that a particular site intends to support; application developers have been asked to decide "where to run what" at design time to develop services using location-specific technologies and interweave them with static resources. Such difficulties stem from lack of adequate infrastructural support for platform-agnostic development and deployment framework. This paper presents the design and implementation of a framework for Web application development which hides the heterogeneity of the Internet and the underlying interaction model. It has been meticulously designed such that it is non-intrusive and requires little change to the existing Web infrastructure. The framework is built on top of a programming model that provides a uniform view across different platforms and thus hides the heterogeneity and distributivity of the Internet. Adaptive deployment involves placement specification and compiler translation. The uniformity gives rise to rapid prototyping and development, thereby reducing costs and improving productivity. The adaptiveness enables QoS aware service provisioning.