Here are the basic requirements, and some hints for getting Maude.
To install maude go to Maude Installation
Core Maude is all you need -- the download is a zip which unzips to a directory maude/
Put that where ever you like to put such things and put associated maude binary in your path. You may like to make a command `maude' (an alias or make a soft link) so you can just type `maude' rather than `maude.linux64' or `maude.darwin64'
If Maude has trouble finding the prelude on startup, set the environment variable MAUDE_LIB to point the the maude directory