Arbil is indeed a metadata editor with support for files.
It used to be an editor for only, the CMDI functionality has been added later on (since the beginning of 2010). This means that the support for CMDI files was not as extensive as the one for IMDI. However, since release 2.3 of Arbil the support for CMDI has been significantly improved.
Note that Arbil is currently no longer maintained and therefore cannot be supported by CLARIN.