Download it. Keep it on your USB stick. Use it when other tools fail due to scale. But learn Gephi or ggplot2 for presenting results.
Pajek is not for everyone, but for its niche – – it remains unmatched, especially given the zero-cost entry . If you need to run a k-core decomposition on a 2-million-edge citation graph, Pajek will finish while Gephi crashes. Just be prepared to learn through the manual and accept that the visuals will need post-processing.
7.5/10 – An indispensable scalpel for cutting into million-node networks, but a blunt instrument for quick, beautiful visualizations.