TagEventor is a project to enable radically simple computer usage by creating physical-object-based user interfaces. It does this using commercially available (and relatively cheap), standardized RFID technology in the form of small, simple USB connected contacted card/tag readers and small, cheap tags. The project was started based on products available from the "touchatag" company, which has clients for Windows and Mac, and run their own Web service to enable many interesting Web-based applications. However, no simple, lightweight Linux client was available, and the Web focus meant that some client-focused functionality was not possible. The software is currently a daemon that monitors the presence of one or more RFID tags on a connected reader and generates "system events" when tags are placed on it or removed from it.
acgtools is a driver for the ACG HF MultiISO RFID reader written entirely in Python and including several developer tools, including EEPROM backup/edit/restoration for enabling some of the more exotic features supported by this hardware. There are also sample applications, notably an e-Passport reader.
LibLogicalAccess is an RFID library developed in C++ for Linux/Windows, also available on C# for use on Microsoft operating systems (using a COM wrapper). It provides low-level commands access and high-level generic abstraction for several chips and readers (PC/SC readers like OMNIKEY, STid readers, etc.) on 125Khz (EM4102, HID Prox, etc.), 13.56Mhz ISO14443/ISO15693 (Mifare Classic, Mifare DESFire, HID iClass, etc.), and 433Mhz frequencies.