Compiling Maude from source
From The Maude System
Maude has been tested on recent versions of GNU C++ 3. Compiling Maude requires GNU bison and GNU flex. The following 3rd party libraries are also required:
A copy (not all the most recent) of sources of the above libraries is also available below.
Here are the sources to Maude itself. Untar and follow the installation instructions in INSTALL.