QSR's NVivo is a popular tool among qualitative researchers. It helps researchers organize, manage, code, and analyze qualitative and mixed-methods research data.

"The purpose of ATLAS.ti is to help researchers uncover and systematically analyze complex phenomena hidden in text and multimedia data. The program provides tools that let the user locate, code, and annotate findings in primary data material, to weigh and evaluate their importance, and to visualize complex relations between them." (Wikipedia)

Ethnographer has been around since the 1980s. While it's currently in v6.0, it's not as polished as other qualitative software tools.