This software, used to delineate orthologs in OrthoDB, is freely available for standalone computations (see more from https://www.orthodb.org/orthodb_userguide.html#standalone-orthologer-software). It is based on pair-wise assessments of protein sequence homology between complete genomes and subsequent clustering. Orthologer includes an optional mode to perform hierarchical computation of orthology guided by a user-provided organism taxonomy.