While broadband, always-on internet connectivity is expanding its reach to ordinary households, application environment infrastructures to allow effective use of this environment are still in their developmental stages. We are designing and implementing the "SOBA Framework", which is an application framework that effectively uses this environment, especially for communication. The SOBA Framework provides the high-level structure to allow communication over the Internet using Peer-to-Peer technology. The core concept of our framework is dynamically configurable shared space. In a shared space, participants can communicate by sharing both streaming media distribution and application behavior. These shared spaces can be dynamically split and merged depending on users' needs as in realworld. Our framework is a base of various advanced applications for real-time communications on the Internet. In this paper, we explain the design philosophy, structure, and implementation of the "SOBA Framework."