This collection contains Java (≥8) software distributed by the Laboratory for Web Algorithmics (LAW), and it is usually linked to some publication. If you find our software useful while working at a scientific publication, please cite us properly, either using the publications quoted in the documentation, or contacting us for suggestions.

We try to distribute everything under the GNU General Public License or the GNU Lesser General Public License.

## Highlights

- Statistical tools to compute efficiently Kendall's τ and the weighted τ.
They include tools to limit accurately
the precision of the involved ranks, as the noise caused by approximation can significantly alter the computation of τ
(see “Traps and pitfalls of topic-biased PageRank”, by Paolo Boldi, Massimo Santini,
Roberto Posenato, and Sebastiano Vigna, in
*WAW 2006. Fourth Workshop on Algorithms and Models for the Web-Graph*, volume 4936 of Lecture Notes in Computer Science, pages 107−116, Springer–Verlag, 2008). - The largest publicly available set of classes and documentation
related to spectral ranking. It includes a detailed
explanation of theoretical formulations and of the algorithms actually
implementing them. In particular,
`PageRankParallelGaussSeidel`

is our best-of-breed implementation of PageRank, whereas`PageRankFromCoefficients`

makes it possible to compute PageRank and its derivatives for every value of the damping factor using the precomputed coefficients of PageRank's power series (using the results described in “PageRank: Functional dependencies”, by Paolo Boldi, Massimo Santini, and Sebastiano Vigna,*ACM Trans. Inf. Sys.*, 27(4):1−23, 2009). You can also compute, for instance, the dominant eigenvector and Katz's index. - A highly scalable implementation of the Layered Label-Propagation algorithm.
`ConsistentHashFunction`

implements the consistent hash function used by UbiCrawler.