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.
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.
FuzzyIndex indexes text for performing fuzzy searches using PHP and SQLite. It can process a list of text strings and build a database which indexes snippets of those strings and the locations where they appear. The class can also search for given keywords and returns the locations of the indexed strings where the best-matching text appears. It uses SQLite to store the indexed text database, but the class can be extended to use a different database type. It uses certain heuristics to extract the snippets from the indexed text. These heuristics are implemented as separate classes which can be used interchangeably.
Colossal Mind Language Detector detects a user's preferred language. It parses the HTTP Accept-Language header and determines the most suitable language for the user from a list of supported languages. The detected language can fallback to a language associated with the user's country in case the Accept-Language header is not sent by the browser. The detected language can be stored in a cookie to avoid needing to detect the language again in subsequent requests.