A software infrastructure is fundamental to a Smart Space. Previously proposed software infrastructures for Smart Space (SISS) did not sufficiently address the issue of performance and usability. A new solution, Smart Platform, which is focused on improving these aspects of a SISS, is presented in this paper. To optimize its intermodule communication performance, the stream-oriented communication is distinguished from the message-oriented ones, and a corresponding hybrid communication scheme is proposed. To improve the usability, a featured loose coupling structure, a straightforward Publish-and-Subscribe coordination model as well as a set of user-friendly deployment and development tools are developed. Besides, Smart Platform is intended as an open and generic SISS available for other research groups. To this end, XML-based message syntax and the open wire-protocol based architecture are adopted to make sharing research efforts more easily.