Gang scheduling has been widely used as a practical solution to the dynamic parallel job scheduling problem. Parallel threads of a single job are scheduled for simultaneous execution on a parallel computer even if the job does not fully utilize all available processors. Non allocated processors go idle for the duration of the time quantum assigned to the threads. In this paper we propose a class of scheduling policies, dubbed concurrent gang, that is a generalization of gang-scheduling, and allows for the flexible simultaneous scheduling of multiple parallel jobs, thus improving the space sharing characteristics of gang scheduling. However all the advantages of gang scheduling such as responsiveness, efficient sharing of resources, ease of programming, etc., are maintained.