When I changed my website’s theme a few weeks ago, I read an intriguing set of instructions in the template’s source files which suggested that I should download Abobe Fireworks to edit the site’s logo (top-left corner), which was stored in a PNG file.
I’ve worked with PNG graphic files for some time and was thinking that the author of the theme must have missed something since PNG only contain graphics, like JPG or BMP files. I still gave it a chance and downloaded a trial version of Adobe Fireworks, then proceeded to open the file. Instead of only finding a static image, I was quite surprised to find an entire design file with layers and editable text. It turns out that Fireworks uses the PNG format to store visual AND design information. If you open up the file in any other application, you will only see the visual information, but with the right tool, you can make any changes that you want to the file. Quite clever.
I guess that you learn something new every day. For more information on the Fireworks PNG format, you can read an article on Adobe’s site here.