The HTML redirect service is particularly useful, because one can start at the Bio2RDF page, and follow a link that looks like "http://bio2rdf.org/html/namespace:identifier", to get to the original providers web page.
There are currently 142 namespaces that are registered along with HTML pages. Examples of these links are, the NextBio page for Amyloid Beta precursor protein (http://bio2rdf.org/nextbio:1445), the NCBI Entrez Geneid page for Superoxide dismutase 1 (http://bio2rdf.org/geneid:6647), the Pharmgkb page for Superoxide dismutase 1(http://bio2rdf.org/pharmgkb:PA334), and the HGNC page for Superoxide dismutase 1 (http://bio2rdf.org/hugo:SOD1).
The list below, details the namespace prefixes that are currently registered with Bio2RDF for this service. A full set of details about what services are provided for any particular namespaces are provided at here, and the entire RDF configuration that makes the Bio2RDF system work is available here (RDF/XML)
aceview, agi_locuscode, arrayexpress, asap, aspgd, aspgd_locus, aspgd_ref, bind, biogrid, biomodels, biopatml, biosystems, brenda, cas, cath, ccds, cdd, cgd, cgsc, chebi, chemidplus, cid, citations, cog, cpath, cpd, dbpedia, dbsnp, ddbj, dictybase, dictybase_trials, dip, doi, dr, drugbank_drugs, ec, echobase, eck, ecogene, embl, ensembl, enzyme, flybase, gdb, genbank, genedb_pfalciparum, genedb_spombe, geneid, gi, gl, go, goa_ref, gopubmed, gr, gr_gene, gr_protein, gr_qtl, gr_ref, h-invdb, h_inv, hgnc, homologene, hpa, hpa_antibody, hprd, huge_navigator, hugo, intact, interpro, ipi, iproclass, isbn, issn, keywords, lifedb, linkedct_trials, ma, mesh, metacyc, mgc, mgi, msdchem, myexp_user, myexp_workflow, nar, ncbi, nextbio, nist_chemistry_webbook, nmrshiftdb_molecule, oclc, omim, pamgo_vmd, path, pathguide, pdb, pdbsum, pfam, pharmgkb, phosphosite, po, prints, prodom, prosite, pseudocap, psimod, pubchem, pubmed, reactome, rebase, refseq, rgd, rn, scop, seed, sgd, sgd_locus, sgd_ref, sgn, sgn_ref, sid, sider_drugs, sider_sideeffects, smart, so, srs, swoogle, symbol, tair_arabidopsis, taxon, taxonomy, tc, tgd_locus, tgd_ref, um-bbd, uniparc, uniprot, uniref, unists, wikipathways, wikipedia, xenbase, zfin
If you know of a biological database that has webpages for their items and is not listed here then feel free to comment about it here or email the group at firstname.lastname@example.org