geoLink is a networked GEOS application for the Commodore 64 written by ShadowM using the ip65 network stack. What you need is a Commodore 64, a 1541 disk drive or the 1541 Ultimate and a RR-Net compatible cartridge (1541 Ultimate, RR-Net, MMC Replay or FB-Net). You can download a .d64 image on the web page with GEOS 2.0 and the IRC client.