Patients receive 1 of 3 salvage regimens. Treatments A and B include delavirdine, 1 of 2 doses of indinavir, and 2 nucleoside reverse transcriptase inhibitors (NRTIs) to which the patient has not been exposed. Treatment C includes ritonavir, indinavir, and 2 NRTIs to which the patient has not been exposed. When virologic failure is first observed, the patient must return in 2 weeks for confirmation of failure and start the salvage regimen within 1 month of the first assay in which failure was observed. Patients who have less than 400 copies/ml HIV RNA after 16 weeks of therapy are considered responders and continue on the study. Those who have more than 400 copies/ml after 16 weeks of therapy are considered nonresponders and should be discontinued from the study. In addition, patients who respond and subsequently rebound with a viral load 0.5 log above the nadir and greater than 400 copies/ml on 2 consecutive assays at least 2 weeks apart are considered treatment failures and should be discontinued from the study. Patients have regular physical exams, as well as virologic, immunologic, and pharmacokinetic assessments.