Exec-PHP is the best plugin i ever use. Just download from http://bluesome.net/post/2005/08/18/50/.
Exec-PHP enable you to run PHP and script from your blog. It’s easy to install, just follow the note. If you’re PHP programmer and want to enhance your blog, it’s recommended to install this plugin to your wordpress blog.

Technically Exec-PHP executes code inside of arbitrary text by wrapping the whole text into “? > < ?” php tags and hand it over to the PHP eval() function. This requires that the executable code itself is encapsulated into “< ? php ? >” tags. By that no parsing of your code needs to be done by the plugin itself.

Difference to similar plugins

There are a lot of PHP plugins available all doing slightly different things. The following list was gathered back in the beginning of 2007 and may not be complete and probably outdated because some of the plugins may have been updated, including more features. Therefore the names of the compared plugins are given including the version number.

Sniplets
The Sniplets plugin by John Godley seems to be a good alternative to Exec-PHP. Although it is harder to configure than Exec-PHP, you may gain some improvements in security due to the way the Sniplets plugin is working.

RunPHP 0.2.2 (Mark Somerville)
The RunPHP plugin by Mark Somerville uses XHTML tag syntax to separate code from HTML. It does strange conversions to “fix” texturized posts and does not support WordPress’ 2.x roles and capabilites system.

RunPHP 2.1.1 (James Van Lommel)
The RunPHP plugin by James Van Lommel creates parsing errors with most of the test code below.

PHP Exec 1.7
The PHP Exec plugin by Priyadi Iman Nurcahyo uses XHTML tag syntax to separate code from HTML. It does strange conversions to “fix” texturized posts.

EzStatic 3
The EzStatic 3 plugin by Owen Winkler