ARM D: ABC plus EFV plus adefovir dipivoxil plus NFV. [AS PER AMENDMENT 06/29/98: Enrollment to Group B is closed to accrual. Group A patients with HIV-1 RNA of 200 copies/ml or more on 2 consecutive determinations may continue their assigned treatment or seek best alternative antiretroviral therapy, which may include access to ABC. Group B patients with plasma HIV-1 RNA of 500 copies/ml or more may continue their assigned treatment or seek best available antiretroviral therapy, which may include access to ABC, EFV, and adefovir dipivoxil with L-carnitine supplementation. Group C patients with HIV-1 RNA levels above 2,000 copies/ml and Group D patients with levels above 500 copies/ml may no longer be randomized to a treatment arm in Group B. Such patients may continue their assigned treatment or seek best available therapy, which may include access to therapy as per Group B patients.] [AS PER AMENDMENT 06/16/99: Study treatment for Groups B, C, and D has been completed. Group A patients with a confirmed plasma HIV-2 endpoint who remain on study may have access to ABC while on study.] [AS PER AMENDMENT 12/27/01: With Version 4.0 of the protocol, many of the metabolic assessments and the cardiovascular risk assessment will be repeated, and a self-reported questionnaire of body shape changes will be added. In addition, an investigation of the effect of long-term IDV on pyuria/hematuria is added, as well as a study of HIV-1 RNA in peripheral blood mononuclear cells (PBMCs).]