Carrier Agnostic 3rd party Integration products

Summary:

Content (required):

FedEx has historically been against interfacing with connectship and the newer shipexec, as those are UPS-owned products. We have learned recently that their aversion to connectship is being lightened, but they will still not interface with shipexec. Their recommendation, should we stay with these UPS products, would be to utilize an interface program to ‘mask’ the usage of connectship/shipexec with their platform.Could you suggest any more carrier-agnostic 3rd party products which have worked well?

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):