Enblend is a tool for compositing images. Given a set of images that overlap
in some irregular way, Enblend overlays them in such a way that the seam
between the images is invisible, or at least very difficult to see. Enblend
does not line up the images for you. Use a tool like Hugin to do that.

Requires GLEW, OpenEXR and libxmi, available at SlackBuilds.org.