Batch queues on Unix?

[Ralph Finch]

We run lots of long-running numerical models.  Is there a true batch
queing system available on Unix?  Specifically, SunOS 4.x.  Desired
features would be:

Queing:  as one job finishes, the next in the queue starts

Variable number of jobs:  the queue can be set up so as to allow 1, 2,
... n jobs running simultaneously.

Different queues with different priorities.

Optional notification when jobs finish.

Thanks,
-- 
Ralph Finch
...ucbvax!ucdavis!caldwr!rfinch