If you are looking for the OpenEdge Developers Kit: Classroom Edition then you need to visit the specific group called the OpenEdge Classroom and join the group.

Details of how to download and install this free edition of the OpenEdge Developers Kit is described in this document, which helps with some of the prerequisites, storage requirements and timing of the download and install process.

You should also read the posts on the Classroom Wall to find out more about getting started with OpenEdge.