PTGui is panoramic stitching software for Windows and Mac OSX. Originally developed as a Graphical User Interface for Panorama Tools (hence the name), PTGui now is a full featured photo stitching application.
PTGui comes in two versions: PTGui and PTGui Pro. The main difference between the two versions is support for HDR stitching, viewpoint correction and vignetting, exposure and white balance correction in PTGui Pro. Click here to compare the features.