The 3-D Nanoelectronic Modeling Tool (NEMO 3-D) is an electronic structure simulation code for the analysis of quantum dots, quantum wells, nanowires, and impurities. NEMO 3-D uses the Valence Force Field (VFF) method for strain and the empirical tight binding (ETB) for the electronic structure calculations. Various ETB models are available, ranging from single s orbitais (single band effective mass), over sp3s* to sp3d 5s* models, with and without explicit representation of spin. The code is highly optimized for operation on cluster computing systems. Simulations of systems of 64 million atoms (strain) and 21 million atoms have been demonstrated. This implies that every atom is accounted for in simulation volumes of (110nm)3 and (77nm)3, respectively. Such simulations require parallel execution on 64 itanium2 CPUs for around 12 hours. A simple effective mass calculation of an isolated quantum dot, in contrast, requires about 20 seconds on a single CPU. NEMO 3-D therefore offers the opportunity to engage both educators and advanced researchers, utilizing a single code. nanoHUB.org is the community web site hosted by the Network for Computational Nanotechnology (NCN) dedicated to bridge education, research, and development for the whole nanoscience and nanotechnology community. This paper reviews the mission of the NCN exemplified by the development and deployment of the NEMO 3-D tool.