This work presents a comparative study between two frameworks oriented to the development of what are known as lightweight clients and web 2.0 applications. The two platforms analyzed are Google Web Toolkit and jMaki. The study is based amongst other factor in two prototypes based on a banking model and focuses on the development based on graphical components with high interactivity. The document includes also an extensive research work about web 2.0 (terms, technologies, etc.) and some popular and successful applications as for example Amazon or Google Maps. The study tries to answer what 2.0 elements made those products and companies special.