Now this is an interesting plugin. One, for its features and two, because of the way the author has documented the plugin. It’s amazing how much time they must have spent on documenting it all. Take a look for yourself Exec-PHP.
The idea of this plugin is that you can add and execute PHP code to static pages and even blog posts through your WordPress site. If you didn’t have this, you would have to enter to code by editing the files of your theme and it may not work the same way as you might possibly want it to.
Now this is truly very well documented and the author also compares their plugin to other peoples’ plugins similar to them. So it’s an interesting read even if you read little snippets of it.