Before getting the actual source code you need to get familiar with subversion and its tools. Visit the subversion reference to discover the basics about subversion and the subversion configuration page to configure subversion properly for this project.
Getting the source code
The URL for the repository used to host EiffelStudio's source code is https://svn.eiffel.com/eiffelstudio/ .
To get all the source code at once simply do:
svn co https://svn.eiffel.com/eiffelstudio/trunk EiffelStudio
This will create a EiffelStudio directory in the directory where the above command was entered.
However to compile EiffelStudio you don't have to checkout the whole repository. Check Compiling EiffelStudio page for more details.
Getting the source code with TortoiseSVN (Windows)
First install TortoiseSVN. Then create a new folder for the source code. In this folder you choose "file > tortoiseSVN > Import". URL for Repository is
after that, you click on the dots (...) where you can choose what to download (maybe only src?). on the folder you need, you click right and then "export", enter the path to you code-folder and you're done.
Getting the source code with SCPlugin (OSX)
First get the latest version of SCPlugin from http://scplugin.tigris.org/. The install will require you to log off and log on to enable the Subversion context menu within Finder. Create a new folder for the source code. Right click on your desktop and click New Folder. As of 0.7.1 you need to do an initial checkout from the command line in order to accept the SSL certificate from origo.ethz.ch Open up Terminal and change directory to your newly created folder from above. Do an initial checkout "svn checkout https://svn.eiffel.com/eiffelstudio/trunk" It will ask you if you want to reject the certificate, accept it temporarily or permanently. Push 'p' for Permanently. You can now use the Subversion context menu by right clicking on your folder created above -> More -> Subversion.
How to get the old releases
The SVN repository also contains old releases of the EiffelStudio environment (up to version 5.4). Those versions can only be compiled with the version of EiffelStudio for that release.
The source code can be found in the subdirectories of the branches directory of the svn repository. The naming convention is `Eiffel_YY' where YY is the release version (e.g. 57 for 5.7).