RSD a system developed by MINOS to simplify installation of the MINOS offline code on remote machines. It is specifically aimed at the GRID environment but could be used in any situation where it is only required to install a frozen version of the code (i.e. no CVS updating).
RSD is part of GridTools
DCM is a utility to support GRID data transfers. It has a list of locally available Store Elements (SEs) from which it builds catalogues and then uses these to locate and transfer files to and from local disk.
DCM is part of GridTools
Ganga is an OO job submission system written collaboratively by Atlas and LHCb and used by them and groups in other disciplines. It's based on the idea of a Job object that is configured, submitted, interrogated about job status and then used to retrieve the output. Job objects can be collected into arrays and processed in parallel.
Ganga is NOT part of GridTools; GridTools simply contains the MINOS extensions to it.
Each of these tools can be used independently and outside a GRID context: RSD can be used to install code on a farm, DCM can retrieve files from the FNAL Enstore and Ganga can run jobs on PBS farms. So there is a forth component to GridTools:-
Eventually here will be found everything necessary to develop and operate GRID production systems based on the above tools. It will include scripts to set up the environment necessary to run the tools, either from a User Interface (UI) i.e. a front-end or a Worker Node (WN) i.e. back-end and also the jobs scripts that can be used as a starting point for GRID production work. For further information on using the tools in a GRID context see Grid Scripts.