VisualHDL

VisualHDL is an integrated development environment (IDE) for developing hardware using VHDL and THDL++. It supports code completion, code navigation, design visualization and tons of other useful features. The IDE is fully integrated with Xilinx ISE toolchain. Moreover, a command-line THDL++-to-VHDL compiler can be used in conjunction with any other tool, that understands VHDL.

THDL++ is a new generation hardware definition language, that provides the flexibility and scalability of C++ while having fully VHDL-compatible semantics. The key elements are, as in VHDL, entities, signals, processes and functions, but you can increase their flexibility exponentially by using inheritance, templates and policy classes. THDL++ language is easy to learn: switch from ADA-like "begin/end" from VHDL to C-like {} and you can start programming basic things. Explore advanced language features one-by-one when you feel ready to make your code more flexible and scalable.