Paint Shop Pro (PSP) is a bitmap graphics editor for computers running the Microsoft Windows operating system that is published by the Minneapolis-based Jasc Software. It is popular among web designers.
PSP was distributed as a shareware, but now is sold for $100, or after rebate, $50 -- which is considerably lower than Photoshop, the 1990s and 2000s market leader in pre-print bitmap image processing. The difference in price between the two programs is due to the fact that JASC is a smaller, less famous company, and the more limited selection of tools on PSP. PSP is also reputedly slower in some advanced functions, like dust & scratch filters.
As a result of its lesser functionality, its learning curve is quite rapid.
With the PSP download is bundled another graphics program called Animation Shop, which is separately sold for $40.
See Also
Wikipedia:Basic bitmap image editing for practical advice on using Paint Shop Pro