Norman Ramsey is now Research Assistant Professor in the Deparment of Computer Science at the University of Virginia. He works on the Zephyr project to build a National Compiler Infrastructure and supports the toolkit as time permits.
The toolkit's specification language is now called SLED, which stands for Specification Language for Encoding and Decoding. You'll see this acronym in our papers, and perhaps one day in the manual.
Version 0.5 contains many bug fixes, and it has some support for automatic generation of assemblers and disassemblers.