Software assets from existing Earth science missions can be reused for the new decadal survey missions that are being planned by NASA in response to the 2007 Earth Science National Research Council (NRC) Study. The new missions will require the development of software to curate, process, and disseminate the data to science users of interest and to the broader NASA mission community. In this paper, we discuss new tools and a blossoming community that are being developed by the Earth Science Data System (ESDS) Software Reuse Working Group (SRWG) to improve capabilities for reusing NASA software assets.