To access the new programming environment packages, you must add the following statements to your .cshrc . These statements must follow all other path setting code. Users with .login files are reminded that the .login file is executed after the .cshrc file and should therefore not contain any path setting code. There is a default version of each component of the Programming Environment. Other versions of the component can be accessed by using the module switch command.
More information is available via the man module and man modulefile commands.
Providing a Flexible User Environment describes modules in more detail.