Some links and information I collected about VHDL and FPGA: 

• VHDL model of DLX written by Peter J. Ashenden. The DLX processor is a RISC machine. Detail can be found in the book Computer Architecture: A Quantitative Approach.
• The Designer's Guide to VHDL, 2nd Edition written by Peter J. Ashenden.
• VHDL Cookbook written by Peter J. Ashenden.
• "Optimizing VHDL code for FPGA targets" from Michael Gschwind and Valentina Salapura.
• Hamburg VHDL Archive.
• Acellera - Unification of Open Verilog International and VHDL International.
• TestBenchTool - Easy Generation of Test Vectors for VHDL Designs.
• VHDL.ORG - EDA Industry Working Groups.
• SIGDA- ACM Special Interest Group on Design Automation.
• MRCI - FPGA Database
• MOSIS - Mosis Foundry
• Opencores - Open source VHDL and Verilog
  

• Aldec
• Altera
• Freescale
  
• Logical Devices Inc.
• Mentor Graphics
• QuickLogic
• Synopsys
• Xilinx