Verified answer

To be viewed by all browsers, a graphic has to be in either the .jpg or .gif format. Almost any graphics program can save in this format.

Photoshop has a dazzling array of abilities that no other graphics program I am aware of has. If you are planning on doing professional level graphics, Photoshop is the only way to go.

OTOH if you simply need to create good graphics for the web, Paint Shop Pro can do some really good stuff. It doesn't come cheap either, but you might want to check it out and perhaps download a free trial version at http://www.download.com/3000-2192_4-10585273.html

If you need a completely free program, you can try the Gimp at http://www.gimp.org/ and/or Paint.net at

http://www.getpaint.net/index2.html

You can download a trial version of Photoshop at http://www.adobe.com/downloads/ The latest version is Photoshop CS3.

Paint Shop Pro can still make decent blends, maybe some extra work is needed but it only costs about $100

I think it's the ability to be viewed by all browsers.

because it is big and it has more options for editing photos