St.Kliment Ohridski University of Sofia: Network-related software
Academic node unicom.acad.bg: Has a number of network-related softare products and tools (Experimental)
Communication & Information Technologies Ltd.: Network-related software as well as publicly available software of some local software vendors

EUnet - Bulgaria ftp site: The first ftp server in Bulgaria is hosted by Digital Systems - the local EUnet provider in Bulgaria which is located in the city of Varna. Has mostly networking and other software tools. (Look into /pub directory.)