There are provided, inter alia, acyclic nucleoside phosphonate compounds having reduced toxicity and enhanced antiviral activity, and pharmaceutically accepted salts and solvates thereof. There are also provided methods of using the disclosed compounds for inhibiting viral RNA-dependent RNA polymerase, inhibiting viral reverse transcriptase, inhibiting replication of virus, including hepatitis C virus or a human retrovirus, and treating a subject infected with a virus, including hepatitis C virus or a human retrovirus.
