FedEx® Advanced for Merchant 5.x

Finally, a robust FedEx shipping module! It offers many more configuration options than Merchant's standard FedEx module, such as calculation taking into account dimensional weight, and declared value insurance. In addition, it lets you configure products to be shipping independently in their own box (or multiple quantity per box) and from their own zip code. Individual products can be flagged to have free shipping, products being shipping in their own box can be specified to have free shipping on a per-method basis (eg. free FedEx Home Delivery for product x), and individual methods can be configured to be free (eg. free FedEx ground). Individual methods can be discounted (eg. FedEx Ground 25% off). Individual methods can also have specific handling charges assigned to them. The merchant can specify themaximum weight to put into individual shipping boxes as well as a maximum number. The module uses a sophisticated algorithm to pack the boxes to the maximum weight while maintaining the lowest number of boxes. The methods seen by the customer in the drop down shipping selection list can be sorted either ascending or descending (or not at all).

The module calculates it's rates by direct XML communication with FedEx's servers and obviously offers FedEx's shipping options but otherwise is similar in functionality to the UPS Custom Integration. 
The module supports international destinations and can also be used by Canadian stores. 

Documentation can be downloaded here in pdf format.