Free CAD tools
 

Includes a VHDL compiler and simulator, logic synthesis tools, and automatic place and route tools. Spice simulation is missing, but there are many free Spice
simulators like Winspice, etc.

http://www-asim.lip6.fr/recherche/alliance/

Design Flow Documentation is herein:
http://www-asim.lip6.fr/recherche/alliance/doc/design-flow/flow.html

This is a good one too
http://www.vlsitechnology.org

Enjoy! :D