The grid middleware is a software layer whose main role is to act as an abstraction layer between the resources (CE, SE,…) of grid sites and the grid users. Thanks to this layer, users can ignore the technical details of the resources and use high-level commands to interact with them. For example, if a user wants to submit jobs to grid computing element, he doesn’t need to know if its batch system technology is SLURM or Torque or HTCONDOR… because he will use the high-level command dirac-wms-job-submit that doesn’t need the batch system technology to be specified.

An other role of the middleware is to integrate the sites and their resources in the global grid infrastructure (in our case, the BEgrid site into the EGI infrastructure).