Some of the tools we used in my computer engineering curriculum were HDL Designer from Mentor Graphics and some tools from Xylinx that were similar. If I remember correctly the reps from Caterpillar said they invested in HDL Designer pretty heavily as it was used widely there. I mention Caterpillar specifically because their world headquarters was about an hour and a half down the road and they recruited pretty heavily from UIUC.

HDL Designer was cool but it was pretty outdated looking even 5 years ago when I was at school. It was all motif running on Sparc Solaris boxes.