This document summarizes various anti-viral and anti-fungal agents. It discusses the mechanism of action and clinical uses of nucleoside reverse transcriptase inhibitors like zidovudine, didanosine, lamivudine, emtricitabine and others for treating HIV. It also covers anti-herpes drugs like acyclovir, valacyclovir, famciclovir and penciclovir; anti-CMV drugs like ganciclovir and cidofovir; and other agents for treating hepatitis, influenza and fungal infections. The adverse effects and pharmacokinetics of many of these drugs are also summarized.