Instant Multi-Tier Web Applications without Tears

We describe how development productivity for multi-tier web-based database 'forms' oriented applications can be significantly improved using 'InstantApps', an interpretive framework that uses efficient runtime model interpretation and features an integrated 'wysiwig' 'point-and click' design editor for developing forms, database schema, control flow, and functional logic. As compared to related academic as well as commercial work, our approach has the distinct advantage of retaining an industry standard architecture that yields high performance and enables model driven functionality to be augmented with hand-written extensions using a well known architectural style and leveraging standard skill sets. In particular, the interface's 'look and feel' can be completely custom built even as the application functionality is developed using the instant 'WYSIWYG' editor. Efficient implementation of interpretation and reflection ensures that performance does not suffer, and performance benchmarks support this. Significant productivity benefits are demonstrated with case-studies of real-life applications developed and deployed on this platform, including actual costs vs. estimates using industry-standard function-point based measures. Finally, we describe some interesting features of the platform, including multi-tenancy and weak meta-circularity, and how these are being exploited successfully in practice.