NNetwork Analysis, Visualization, & Graphing TORonto is a software system for scalable visualizing and analyzing networks. NAViGaTOR is a powerful graphing application for the 2D and 3D visualization of biological networks. NAViGaTOR includes a rich suite of visual mark-up tools for manual and automated annotation, fast and scalable layout algorithms and OpenGL hardware acceleration to facilitate the visualization of large graphs. Publication-quality images can be rendered through SVG graphics export. NAViGaTOR supports community-developed data formats (PSI-XML, BioPax and GML), is platform-independent and is extensible through a plug-in architecture (KR Brown et al., Bioinformatics. 2009 Dec 15; 25(24): 3327–3329) Registration not required.