Greycite will now return citations in RIS format , though with the caveat that the Type record value is always set to be ELEC – it is difficult in general to infer any other type information from a resource.
I have also added support for the Wikipedia citation format. This has the benefit that you can include information about archives in the data, however you appear only to be able to include a single archive should there more than one. The format insists that you include a date for the archive which makes referring to webcitation.org archives  difficult as there is no easy way that I have found to get at the archive date so webcitation.org links are currently not reported. Work in progress….