- Compare Multi Organism Information System
- EggNog evolutionary genealogy of genes: Non-supervised Orthologous Groups
- EnsemblCompara
- Evola Evolutionary annotation database
- Genomicus Genomes in evolution
- HCOP HGNC Comparison of Orthology Predictions
- HomoloGene
- Inparanoid eukaryotic ortholog groups
- IsoBase A Database of Functionally Related Orthologs
- Metazome database and graphical user interface enabling comparative genomic studies within the metazoa
- OMA (Orthologous Matrix project)
- OPTIC Clade genomics web server
- OrthoDB The Hierarchical Catalog of Eukaryotic Orthologs
- OrthoInspector
- OXGRID the Oxford Grid project
- P-POD Princeton Protein Orthology Database
- Panther Classification System
- PHOG PhyloFacts Orthology Group
- PhylomeDB
- TreeFam Tree families database
- VISTA Tools for Comparative Genomics
