 There are several modern Windows based FidoNet Mailers available today with source code, including Argus, Radius, and Taurus.MainDoor is another Windows based Fidonet mailer, which also can be run using either a modem or directly over TCP/IP.Two popular free and open source software FidoNet mailers for Unix-like systems are the binkd (cross-platform, IP-only, uses the binkp protocol) and qico (supports modem communication as well as the IP protocol of ifcico and binkp).