The extensible NEXUS file format is widely used in phylogenetics, evolutionary biology, and bioinformatics.
It stores information about taxa, morphological character states, DNA and protein sequence alignments, distances, and phylogenetic trees.
[1] The NEXUS format also allows the storage of data that can facilitate analyses, such as sets of characters or taxa.
Many popular phylogenetic programs, including PAUP*,[2] MrBayes,[3] Mesquite,[4] MacClade,[5] and SplitsTree,[6] use this format.
Nexus file names typically have the extension .nxs or .nex .