phpAES is a PHP 5 class (PHP 4 now included). It can encrypt/decrypt data using 128, 192, and 256-bit AES cipher. It uses pure PHP and does not require mcrypt or any other external library to be compiled into PHP.
Supported cipher modes include: Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), and Output Feedback (OFB). There are two versions of phpAES, the free version of phpAES only supports ECB mode while the paid version supports all modes.
phpAES comes with a sample script and the phpAES class file, includes full source code.
phpAES meets the specifications as outlined by FIPS 197 (Federal Information Processing Standards Publication 197) available at http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf.