Where we can test the SAP objects by using eCATT?

Hi Abapers,

Where we can test the SAP objects by using eCATT?Is there any separate software or tool we have to install or its included in the SAP itself?

I have ECC5.0 version?how can i configure or install eCATT?

Please explain the step by step procedure?

Early reply is highely appriciable.

Regards,

Chow.