One of the large debates raging in ecash development
is over how standard ecash should be, or how many
versions should be in use.
Microsoft and Visa, for example, are looking at
publishing "specifications that make secure transaction
technology available to other software vendors and card
systems to implement themselves or license from Microsoft."
While folks like Visa, Microsoft, and Mastercard 
debate the value of standards, a number of smaller
companies are issuing a number of different systems.