Multi Carrier Shipping fullfilment module? software?

Hi, this is not directly a zencart question(tho it can be quite useful for it) so much as it is a query about what other people are using when it comes to shipping packages from their warehouses/offices.

We currently use StarShip to schedule package pickups for USPS and FedEx as well as printing the shipping bar codes for those two and UPS. After looking around for a bit most of this companies want an arm and leg for subscriptions.

The thing is... me being a web developer went looking into those three carriers and they all offer free access APIs to schedule pickups, print the package barcodes, get package quotes, etc... so my I guess I'm trying to find out if anyone knows of a module for zencart or stand alone software that plays well with zencart that can leverage those APIs? preferably open source so we can all improve it.

I am almost tempted to look into implementing something myself but I am quite busy with work and I'm really not that well versed with all the shipping terms/form/misc and would have to read/learn up on it