Under the hood, Saxon uses a “resolver” whenever it attempts to load a document (a source document, stylesheet module, unparsed text document, etc.). For the past few releases, the Java, C#, and C products have been using resolvers based on the XML Resolver APIs.
I’ve been working on some improvements to those APIs. It’s likely that the next releases of Saxon will be ship with XML Resolver 6.x.
If you’d like to preview the planned changes and provide feedback about how they work in your applications, that’d be grand.