
1) Information system
Found on
https://www.crosswordclues.com/clue/xcon

The R1 (later called XCON, for eXpert CONfigurer) program was a production-rule-based system written in OPS5 by John P. McDermott of CMU in 1978 to assist in the ordering of DEC`s VAX computer systems by automatically selecting the computer system components based on the customer`s requirements. The development of XCON followed two previous unsu.....
Found on
http://en.wikipedia.org/wiki/Xcon

Xcon is a network backdoor Trojan that communicates through port 8989.
Found on
http://www.probertencyclopaedia.com/LBA.HTM
No exact match found.