Recently on the SWORD mailing list, there has been a discussion as to which new terms should be added to the EDAM portion of the ontology, and which belong in the scope of SWO. For the record (and posterity), here is a summary of the result of the discussion.
The scope of SWO was originally bioinformatics software, and this scope was moved more generally to software in digital preservation later on. EDAM deliberately does not include software, but rather data types and format, operations and objective (with some useful identifier classes as well). EDAM concepts are domain-specific and concern attributes specific to bioinformatics software. This is in contrast to SWO, which (in addition to software classes) contains domain-neutral terminology; SWO is concerned with attributes of software in general, and not just bioinformatics specifically. This of course creates some degree of overlap, especially with data types, formats, and the operation/objective hierarchies (which are currently being resolved). Bioinformatics-specific data types and formats can live in EDAM while software, bioinformatics-based or otherwise, should live in SWO along with the cross-domain parts (e.g. GIF, TIFF).
The domain neutrality of SWO gives us a very strong selling point to other communities / domains, who will want to manage their own ontologies. SWO could be the hub and domain-specific modules would be the spokes. There could / should be a common vocabulary for software in general, across science and the humanities: we can offer SWO (or a simplification of it) to perform this function.
A slim upper level for software could easily be extracted from SWO to give a domain neutral portion. In the near future, it is worth pulling out that upper level SWO as a separate OWL file.