This is an open-label, randomized, pilot, Phase II study of the safety and efficacy of Viracept in combination with modified antiretroviral therapy as treatment in patients with cutaneous and mucosal KS. Patients will be randomized to modify (add or switch or initiate) their current antiretroviral therapy and will add Viracept or remain on their current background antiretroviral therapy for a 2 month period. Initially 20 patients will be randomized in a 2:1 ratio (i.e., 14 Viracept, 6 control) for a 2 month period. Response to therapy will be evaluated at the end of the 2 month control phase. At this point, patients who were initially assigned to the control arm will continue on open label Viracept for an additional 10 month period.