by Tom Garritano, the GRIDS Center -- The National Science Foundation (NSF) Middleware Initiative (http://www.nsf-middleware.org) addresses a critical need for software infrastructure to support scientific and engineering research. Begun in late 2001, NMI funds the design, development, testing, and deployment of middleware, a key enabling technology upon which customized applications are built. Specialized NMI teams are defining open-source, open-architecture standards that are creating important new avenues of on-line collaboration and resource sharing. In addition to the production-quality software and implementation standards created by those large systems-integration teams, NMI funds smaller projects that focus on experimental middleware applications. As a leading part of the emerging cyberinfrastructure, NMI software and services are used by thousands of researchers and educators in the U.S. and far beyond. Examples include scientists who use the Grid to enable community-wide access to massive sets of experimental data; universities who use common tools for authorizing resource access across multiple campuses; users who benefit from Web-based portals that provide a common interface to wide-ranging Grid-enabled computation resources; and individuals who depend on Grid access of instrumentation such as accelerators, telescopes and more. In fall 2003, NMI extended its two original systems-integration projects, the GRIDS Center (Grid Research, Integration, Deployment and Support) and the EDIT consortium (Enterprise and Desktop Integration Technologies). At the same time, a pair of additional teams joined NMI: the Open Grid Computing Environment (OGCE) team, which develops portals for ubiquitous, browser-based access to Grid resources, and the Common Instrument Middleware Architecture (CIMA) team, which develops tools that ease the Grid-enablement of scientific instrumentation. The four teams work independently and together, as situations dictate, to serve broad user communities that require a dependable yet flexible middleware infrastructure. “Before NMI, middleware was in danger of becoming 'balkanized,' with many differing research communities developing independent -- and often incompatible -- solutions to similar problems of interoperability and resource sharing,” said Kevin Thompson, NSF program director for NMI. “Now, by creating production-quality middleware using open-source and open-standards approaches, NMI-sponsored projects avoid duplication of effort and provide a common foundation on which varied communities may build their own customized applications.” Defining and Deploying the Open Grid Services Architecture As the largest of NMI's systems-integration projects, the GRIDS Center (http://www.grids-center.org) is a partnership of leading forces behind Grid computing. GRIDS produces a suite of tested, hardened, and supported middleware that includes the Globus Toolkit , Condor-G, the Network Weather Service, MyProxy, MPICH-G2 and others that are widely used internationally for research and industry. By using GRIDS tools, diverse communities such as NEESgrid, GEON and BIRN avoid the necessity of creating their own infrastructure, yielding greater functionality, interoperability and standardization among projects while maximizing the benefit of NSF's investments. GRIDS leaders are defining the Open Grid Services Architecture (OGSA) that extends capabilities of popular Web services, giving software developers powerful new standardized tools for creating customized applications. Securing Seamless Access to On-line Environments EDIT leads the development of tools and services that facilitate the security of and access to collaborative applications in the research and education communities. Today, researchers maintain several sets of credentials to access resources and services offered by their home organization, institutions of their peers, and collaborating research projects. As they continue to be deployed across the country and abroad, EDIT's identity management tools and implementation guidance will provide seamless access to scientists' available electronic resources, while maintaining their preferred level of privacy and the resource providers' required levels of security. By developing the methods, architecture, and tools to support scalable and manageable authentication and authorization, EDIT is addressing the broader challenge of collaborating electronically with increasingly diverse communities in a global context. Easy-to-Use Grid Portals NMI's two newest teams take advantage of the latest OGSA specifications to, respectively, facilitate the creation of Grid portals and ease the use of Grid-enabled instrumentation. Portals are Web-based user interfaces that simplify the process of identifying and accessing Grid resources. The OGCE team fosters collaborations and sharable components with portal developers worldwide. Tasks include the establishment of a Grid Portal Collaboratory, a repository of portlet and portal service components, an online forum for developers of Grid Portals, and the building of reusable portal components that can be integrated in a common portal container system. Grid-Enabled Instrumentation The CIMA team is using OGSA to develop a standard, reusable Grid methodology for on-line access to instruments. Presently, devices such as synchrotrons, embedded network monitors and wireless sensors can only be accessed with data-acquisition and -analysis applications that rely heavily on specialized knowledge of the instruments. The project leverages two other NSF-funded projects -- the Pacific Rim Application and Grid Middleware Assembly (PRAGMA) and the TransPAC high-performance international Internet project. Leveraging Investments in the U.S. and Overseas Since 2001, NMI has been an outlet for well-tested, deployed and supported middleware based on common architectures that can be extended to Internet users around the world. The initiative leverages past and present investments by other federal agencies and the private sector. With their emphasis on production-quality software and implementation standards, the large systems-integration projects build on and include software developed with support from the U.S. Department of Energy, NASA, DARPA, the U.K. e-Science Program and the European Union. Industry sponsors such as IBM and Microsoft have also contributed to tools incorporated in NMI releases. By funding large systems-integration projects that focus on delivering robust middleware tools, NMI is helping researchers and educators access the emerging cyberinfrastructure. NMI's first two systems integration teams -- the GRIDS Center and the EDIT Consortium have been expanded through 2006, while NMI has added two new complementary teams in the Open Grids Computing Environment (OGCE) portals consortium and the Common Instrument Middleware Architecture (CIMA) team. And the initiative's smaller projects spur development of experimental collaboration tools, essential software libraries for Grid-based parallel computing and tools for Grid databases. In total, NMI provides a growing, stable foundation of middleware for science and engineering research and education. For more information, see http://www.nsf-middleware.org. To participate, send mail to contact@nsf-middleware.org. Primary support for NMI comes from the National Science Foundation program number 4089, awards 0123961, 0123973, 0123937, 0330685, 0330670, 0330634, 0330613, 0330545, 0330652, 0330554, 0329756, 0330568, and 0330626. The NMI teams wish also to acknowledge other sponsors of the individual components, including the U.S. Department of Energy, NASA, DARPA, the U.K. e-Science Program, the Swedish Royal Institute of Technology, IBM and Microsoft.