**Proposal full title:** The full title of the Proposal is 'PyPy: Researching a highly flexible and modular language platform and implementing it by leveraging the Open Source Python Language and Community'. **Proposal acronym:** The proposal acronym is PYPY. **Strategic Objectives:** This proposal directly addresses the Strategic Objective IST-2002-2.3.2.3 - 'Open development platforms for software and services' of the Second Call of the Information Society Technologies Workprogramme. Our primary Technical objective is to build an open run-time environment for the Open Source Programming language Python. This will facilitate the development and production of networked and distributed software systems and services, and embedded software. Our primary Scientific objective is to investigate novel techniques (based on Aspect-Oriented-Programming code generation and abstract interpretation) for the implementation of practical dynamic languages, breaking the compromise between flexibility, simplicity and performance trade-offs and expanding the range (small-to-large) of directly supportable runtime platforms. Our primary Methological objective is to showcase a novel software engineering process, Sprint Driven Development. This is an Agile methodology, providing a dynamic and adaptive environment, suitable for co-operative and distributed development. **Proposal abstract:** .. include:: abstract.asc