The captcha.php library is very user-friendly and extremely easy to integrate into existing forms, because of its simple API. It nevertheless sports many configuration options, like multiple image modes and accessible alternative text riddles. It also has "AJAX" super cow powers and many sensible defaults to frustrate users less than other implementations. It prevents spambot access well, even with its relaxed defaults.
DHCP Lease Query in PHP is a PHP class that will allow you to send DHCPLEASEQUERY packets to inquire about known leases from a remote DHCP server. It is similar in nature to ISC's OMAPI but without the hangs it creates, nor does it cause dhcpd to behave in a single-threaded fashion while talking to it. After all, it emulates an actual DHCP "helper" (relay agent) and, as such, all queries travel over IP. It is based on RFCs related to DHCP and follows the RFCs as closely as possible.
EasyPhpMassEmail is a PHP class that is intended for Web sites that need a simple solution for sending many email messages and do not have access to the PEAR packages for sending mass emails. The EasyPhpMassEmail class sends the email messages in batches and relies on an email queue page that reloads after each batch. By doing so, it is possible to send a large number of emails without problems using the mail() function and have a progress indication at the same time. The example files in the package demonstrate the use of the class.
File upload and validation class is a PHP class that can be used to validate and process uploaded files. It can validate a given uploaded file by checking its MIME type or its original file type, and by checking its file size against a given limit and file type. It currently supports audio, video, PDF, and image file uploads. The class can create a path in the server as well.