In the context of electromagnetic tagging, we present the results from our ongoing work to unify Electronics Article Surveillance (EAS) and Radio- Frequency Identification (RFID) technologies using an open architecture design for tag readers. Two fundamental approaches are presented: microcontroller-based architectures and Field Programmable Gate Array (FPGA) architectures. Using these flexible designs, along with Direct Digital Synthesis of the waveforms, it is possible to create frequency-agile software-reconfigurable hardware which can detect all common varieties of EAS labels and RFID tags. Since much of the functionality can now be performed in software, these new reader technologies can be implemented with little additional cost compared to conventional readers. We present three microcontroller-based design examples of varying complexity ranging in parts cost from $5/unit to $500. Ongoing work with an FPGA-based design is also discussed. Finally, we present a common software interface for all tag reader modules and report on approaches to integrate such tag reader hardware into local area networks and to the Internet using 2-way pager technology and dial-up modems.