igraph is a collection of network analysis tools with the emphasis on efficiency, portability and ease of use. The package is open source and free and has interfaces in R, Python, Mathematica with the core of the package being developed in C/C++.
All the interfaces are maintained in repositories in this GitHub organisation. The governance of the project is available in GOVERNANCE.md. The main website of the project can be found at https://igraph.org. The discussion forum is available at https://igraph.discourse.group/.