Are you looking for panorama stitching software? Otherwise I think I should recommend an audiophile website
Speed isn't the best criteria alone for panorama generating software. Organization of the images to include, lens perspective correction, horizontal and vertical stitching capability, exposure matching and rudimentary other editing features such as cropping are all part of what go in to pano software that stands out. More advance features including High Dynamic Range inputs are becoming standard. There is the need to be able to display or export a large, perhaps odd proportioned file for printing or display.
Pano software is available from many camera vendors and is frequently included with a software package. Cameras are regularly available, mostly compacts or p/s, that allow for in camera stitching or optimization of the shots in camera prior to 'stitching'. Canon and Olympus are two that first come to mind that include versions (differs slightly for different camera models) of panorama stitching/editing software.
Adobe Photoshop editing products (Photoshop, Photoshop Elements) include various automated features to stitch and blend images. The more advanced version also include perspective corrections and content shifting/compression.
Easypano makes software called Panoweaver that is known not only for its Flash output and batch processing, but the fisheye type images it can produce with or without HDR elements. It also has some capability to produce 360 degree images.
Autopano is software built to exploit cameras with moving heads. These are motorized tripod mounts that auto rotate the camera at fixed degrees of rotation and intervals to generate the data to make 'in the round 360 degree' and virtual tour type images that are very large. Big file capability for high resolution of sites like architectural interiors.
Speed of output will be dependent at least somewhat on the number of images to be included and the hardware (computer) running the application.