All the clusters are using SLURM which is widely used and open source http://slurm.schedmd.com .
Running jobs with SLURM
Currently, only Fidis has a serial partition with a "pay-as-you-use" policy. On the other clusters, you will be charged for the whole nodes even if you use only a fraction of them.
In the case you only need a few cores, please make sure to use Fidis' serial partition. Failing to do so will increase the cost of your simulation!
More details can be found on the 2020 Annual Maintenance page.
The normal way of working is to create a short script that describes what you need to do and submit it to the batch system using the sbatch command.