The OpenRMCS is open to everyone. You don't need to register or log in. Comics are saved, but it is not possible to vote on them, edit them, or delete them once submitted.
The RMCS is only open to those who have an account (see How_To_Get_An_Account.) You need to have an account and log in to create comics. Comics are saved, and it is possible for other RMCS account holders to vote on them. The author can edit or delete the comic.