You must run an X windows client like Xming or XWin on your local machine before connecting to a server. After you connect to the server, set your environment variables by tyoing
source $SOFT/cadence
Start cadence with the command: virtuoso
ic 5.1.41, ic6.13
Assure4.1
ius82
mmsim7.11
soc8.10
tsi6.1