TopoR is extremely fast and comprehensive topological PCB autorouter. It routes PCBs with free-angle technology and make arc-like traces. The result is far superior to any shape-based auto-router or even time-consuming manual routing. Specctra DSN/SES interface is supported to exchange data with PCB CAD packages. 650 pin version is available for free. TopoR routes with less number of vias/layers and length of traces if compare to other auto-routers. Each wire has a minimal length and goes around pads with a proper clearance. Absence of preferred routing directions in layers considerably reduces wire parallelism, which in its turn reduces electromagnetic crosstalks. TopoR has intuitive user interface that allows you to learn it and make your first free-angle design in few hours. Before all operations TopoR shows tips that helps in your work. User manual and tutorials guides your through the routing process and allows to get started with ease. TopoR can perform parallel optimization of several alternative topology variants, which differ in optimized parameters, while the user is offered a choice of selecting one or several variants. One the unique features of TopoR is its capability to move components on the routed board while preserving the connections topology. Geometry and positioning of components are automatically calculated to comply with the new components position. Movement of components, vias and wire branching is used to decrease wires length, provide the utmost clearance space which should be not less than required (to eliminate the narrow spaces). Movement can be performed both manually and automatically, and the most effective wires shape is defined immediately. Due to absence of preferred routing directions in layers and deep level of optimization TopoR provides quality routing of contemporary BGA components, which is traditionally a very difficult problem for other routers.
You can download TopoR from http://www.toporouter.com