This work describes basic ideas of lightweight graph visualization system developed in Riga Technical University. Comparison of according existing freeware and shareware solutions is being made. Overall proposed software architecture at high abstraction level is presented along with details of implementation of its mechanisms. This work includes aspects of optimization of force-based graph layout algorithm; description of useful visualization techniques (such as projective shadows, visual data clustering that might be useful in design and analysis routines, etc.). Described ideas were implemented and verified by visualization of large graphs in original lightweight software 3DIIVE. Conclusions about achieved results are also presented.