oauth-php is a PHP library for OAuth consumers and servers. It has an extensible OAuth store, including a full working implementation of a MySQL store. The library implements methods to: verify incoming requests against the library; to sign outgoing requests, with curl support for actually doing the request; to sign requests with a body; to administrate consumer keys and tokens for multiple users (server and consumer side); and to log incoming and outgoing requests handled by the library (optionally in the database).
The OATH Toolkit makes it easy to build one-time password authentication systems. It contains shared libraries, commandline tools, and a PAM module. Supported technologies include the event-based HOTP algorithm (RFC4226) and the time-based TOTP algorithm (RFC6238). OATH stands for Open AuTHentication, which is the organization which specifies the algorithms. For managing secret key files, the Portable Symmetric Key Container (PSKC) format described in RFC6030 is supported.