GNU Taler is a free software-based microtransaction and electronic payment system. The project is led by Florian Dold and Christian Grothoff of Taler Systems SA. Taler is short for the "Taxable Anonymous Libre Economic Reserves" and alludes to the Taler coins in Germany during the Early Modern period. It has vocal support from GNU Project founder Richard Stallman. Stallman has described the program as "designed to be anonymous for the payer, but payees are always identified." In a paper published in Security, Privacy, and Applied Cryptography Engineering, GNU Taler is described as meeting ethical considerations - the paying customer is anonymous while the merchant is identified and taxable. An implementation is provided by Taler Systems SA.