Is there a possibility to load .adf files to Quantum GIS?
Arcinfo .adf files can be raster or vector.
Try Quantum's Add Vector Layer, select source types of Directory and ArcInfo Binary Coverage, and then select the directory containing the .adf files. There will be second dialog asking which sub-layers to add; coverages are a composite datatype that can contain any combination of points, lines, polygons, and annotation.
You can also add the .adf file directly, without choosing the directory type, but then you don't get to choose which geometry to load.