Highly active antiretroviral therapy (HAART) often results in short-term benefits for people with HIV in terms of reduced plasma viral levels and increased CD4 cell counts. When used at an early stage of HIV disease, however, the clinical benefit of HAART is uncertain. Many questions still remain regarding the optimal use of antiretroviral therapies, such as the timing of initial antiretroviral therapy and the composition of the best combination regimen to use initially or after virologic failure. Randomized trials of different starting antiretroviral regimens (e.g., FIRST [CPCRA 058]), different regimens after initial virologic failure (e.g., PIP [CPCRA 057]), and different management strategies for HIV infection (e.g., bis-POM [CPCRA 039], NvR [CPCRA 042], GART [CPCRA 046], and IL-2 VL/Dose [CPCRA 059] are being conducted by the CPCRA. [AS PER AMENDMENT 2/28/01: The MDR-HIV (CPCRA 064) protocol is now included as an example of a different management strategy for HIV infection, whereas the bis-POM (CPCRA 039) protocol is no longer included.] This study provides a mechanism for long-term monitoring of patients enrolled in these trials as well as antiretroviral-naive patients who are either starting treatment or electing to defer treatment.