fCoSE Layout for Cytoscape.js

cytoscape-fcose is a high-performance layout extension for Cytoscape.js, implementing the fCoSE (fast Compound Spring Embedder) algorithm. Developed by the i-Vis Lab at Bilkent University, it is significantly faster than its predecessor, CoSE, offering up to 2x speed improvement while maintaining similar aesthetic quality for graph visualizations. The current stable version is 2.2.0, with releases occurring a few times a year, indicating active maintenance. A key differentiator is its robust support for compound graphs and an extensive set of user-defined constraints including fixed node positions, alignment (vertical/horizontal), and relative placement, which can also be applied incrementally. It achieves this by combining spectral layout techniques with force-directed methods, making it suitable for complex network visualizations where both speed and structural clarity are paramount.