Digital Core Design - VHDL, Verilog synthesizable and simulation models.
Doulos KnowHow - Designer's guides and models for VHDL and Verilog. SystemC home. Also Perl and Tcl/Tk for hardware designers resources.
HDL at Wikipedia - Definitions, resources, and links related to hardware description languages.
Ruby - Ruby is a notation and design discipline intended for the development of regular integrated circuits and similar hardware and software architectures.
Titivillus: Software Development - Links to many programming languages, including several HDLs.
