Both are mobile phone barcodes that store a lot more information than your standard product barcode that you scan at the supermarket.
By encoding information into print, users (or learners) can scan into their mobile phones, information, data, URLs,
So the question you may be asking, which of these two mobile phone barcode systems you should go for?
Well sometimes it is not a matter of comparing the two systems, but asking what device do your learners have and be using.
I have been using an iPhone 3G for nearly a year now and the main issue with using the iPhone and QR Codes is the quality of the camera. Due to the fixed focus it has real issues in acquiring and reading QR Codes. Now the iPhone 3GS has a much better camera and the variable focus does allow it to focus much better on QR Codes and decode them. However I still have issues and both the 3G and 3GS don’t even come close to the scanning ability of the Nokia N95.
So out of curiosity I installed and tried it with my iPhone 3G and was surprised to see that it worked very well.
Now I do have issues with some of the privacy issues relating to Microsoft’s implementation of mobile phone barcodes, but if your learners all have iPhones and specifically the lower specified iPhone 3G then using Microsoft Tags may be a real option in getting learners easy access to information and URLs.