Gem was the graphical interface provided with the Amstrad PC 1640 and 1512 computers, even being XT class computers it was great to have a mouse and graphical interface.
Now actual information about GEM can be located on this link:
http://www.deltasoft.com/

To download GEM and know about the history try:
http://www.geocities.com/SiliconValley/Vista/6148/gem.html

This is the third disk (green one) spanish version


This is a cool tiger image shown on all manuals


The four disks


Amstrad 1512 with the four disks and manual.