Downloads for all platforms are available at http://code.google.com/p/nmrglue/. Tar files are available for UNIX-like systems (Linux or OSX) and a binary installer for Windows.
nmrglue requires numpy and scipy to be installed. Please see the install instructions for these packages for details.
After installing the above dependencies download and extract the source distribution and run:
$ python setup.py install
Download the binary installer and run it.