Prerequisites 

To install GEMS, you will need:

   1. A working Eclipse installation
         1. http://www.eclipse.org (version 3.0+)
   2. The Graphical Editor Framework (GEF)
         1. http://www.eclipse.org/gef
   3. The Eclipse Modeling Framework (EMF)
         1. http://www.eclipse.org/modeling/emf

Obtain and install Eclipse, GEF, and EMF (please see their respective installation guides for instructions). Throughout this guide, we will refer to root folder of your Eclipse installation location as <eclipse_install>.
Obtaining GEMS 

GEMS is available from: http://www.eclipse.org/gmt/gems and also from http://www.sf.net/projects/gems.

Download the latest zip file for GEMS and unzip it to <eclipse_install>/plugins. This should create several new directories in your <eclipse_install>/plugins directory:

   1. org.eclipse.gmt.gems.dsml_X.X.X
   2. org.eclipse.gmt.gems.css.parser_X.X.X
   3. etc.

Validating the Installation 

From the file menu in Eclipse, choose New->Other->GEMS2->Metamodel Model. Select a project for the new model and click "finish".
If a new GEMS metamodel is created and appears in the modeling editor, you have successfully finished the installation.

Installation Troubleshooting: 

If GEMS2 does not show up as a folder in the new file wizard:

   1. Ensure that all of the prerequisite plugins are installed and working properly. Go to Window->Show View->Error Log and check for any errors related to org.eclipse.gmt.gems.* plugins. These errors should tell you if any of the prerequisites are missing.

If a new model shows up but exceptions are thrown in the error log and adding/deleting elements does not work properly:

   1. ...and the org.eclipse.gmt.gems.dsml.kb plugin (Prolog) is installed
      on Windows -the Prolog plugin is the #1 source of errors in GEMS installs...if you don't need Prolog, delete org.eclipse.gmt.gems.dsml.kb and org.eclipse.gmt.gems.dsml.kb.jpl
         1. Make sure SWI Prolog is installed and that the jpl.jar from the org.eclipse.gmt.gems.dsml.kb plugin's lib directory matches the one in the SWI Prolog lib directory


Upgrading or Re-Installing

First, delete your existing GEMS installation by removing ALL plugin dirrectories starting with "org.gems.": 

   1. <eclipse_install>/plugins/org.eclipse.gmt.gems.dsml_X.X.X
   2. <eclipse_install>/plugins/org.eclipse.gmt.gems.dsml.X_X.X.X
   3. etc.

Next, follow the directions above for a new installation. Finally, ***VERY IMPORTANT*** start Eclipse from the command line using the "-clean" option.