Provides complete online language reference and examples of common constructs.
http://www.amontec.com/vhdl_part.shtml
VHDL, Verilog synthesizable and simulation models.
http://www.dcd.pl/
Practical Guide for Designing, Synthesizing and Simulating ASICs and FPGAs using VHDL or Verilog.
http://www.doone.com/hdl_chip_des.html
Lots of VHDL and Verilog resources. Including PaceMaker Self-Teach software.
http://www.doulos.co.uk/
Megafunctions are modular, DSP algorithms and functional blocks for custom use in PLD or ASIC designs.
http://www.nova-eng.com/vhdl.html
The Verilog-AMS Technical Subcommittee has been created with the charter to develop, update and promote analog and mixed signal extensions to the Verilog (IEEE-1364) language.
http://www.eda.org/verilog-ams/
Summit Design, Inc.
http://www.summit-design.com/
Synthesizable VHDL and Verilog HDL IP Cores.
http://www.dcd.pl