The ProThesaurus (Protein Thesaurus) API has two parts; a Biological Mark-up Service and a Biological Name Service. The Biological Mark-up Service scans text for the names or identifiers of biological objects (e.g. proteins) and marks any hits. The Biological Name Service identifies a biological object and provides its name, database identifiers, and other frequently used synonyms.
BeThesaurus (Beta Thesaurus) is an extension of ProThesaurus that allows users to propose their own names and identifiers for biological objects.