[geon]

Imho, '/' should be used to map a specific resource, like a file or a collection of objects in the database.

URL arguments with '?' and '&' should specify a secondary "meta" mapping for things like sorting or filtering, that still acts on basically the same resource.

[ceol]

That's my opinion, as well. However, what about paginating things? A different page is a different set of the same type of object, so it's basically sorting and filtering, but you're returning different content.

    /posts/page/2

    /posts?page=2

    /posts?limit=25&offset=25

I like the third option because it allows the must functionality to the user if they so desire, but it kind of feels like a violation of the "only sorting and filtering" rule.