License: GNU General Public License version 3.0 (GPLv3)
Description From Website: SmillaEnlarger is a small graphical tool ( based on Qt ) to resize, especially magnify bitmaps in high quality. ( The used algorithm is an invention of my own )
I didn't see any results when searching the forums so I thought I would suggest it since it's a great program. I personally use this as it produces great and natural results comparable to commercial resizers and far better than standard scaling methods packaged with image editing software like Photoshop.