CR4E is a client tool. Not sure if there is any separate Server edition for it! It is supposed to be on the client machines (Which is believe would be a windows platform) were developer can make use of it develop the report.
Not sure why SAP would include it with the Linux server installation package. Or it might be optional to download. You can also check if it also exist with Windows and other OS versions.
I guess best way to get the answer is to ask SAP directly and log an incident to get better clarity.