AHDL  
   Altera's HDL.
   http://www.altera.com/support/examples/ahdl/ahdl.html

bluespec  
   Bluespec adds extensions on to System Verilog to raise the abstraction level for complex control logic.
   http://www.bluespec.com/

handel-c  
   A variant of C, handel-c is a behavioral language for FPGA design.
   http://www.celoxica.com/