VeriWell is a full Verilog simulator. It supports nearly all of the IEEE1364-1995 standard, as well as PLI 1.0. Yes, VeriWell *is* the same simulator that was sold by Wellspring Solutions in the mid-1990 and was included with the Thomas and Moorby book
small & quick, very well ! but it does NOT support v2001 and there are some bugs. I fixed a little and forked it to "bitbucket.org/Simuc/veriwell/".