HealthVault is an XML-based API that is accessed over https and can be called from any platform that supports that approach, but there are caveats to doing so.
You should start by reading our announcement to understand how we are approaching this area.
The following libraries are currently available:
All of these libraries are currently in an early state of development, and partners that use them are likely to be writing a fair amount of library-level code themselves. There are a few things that we're doing to make that process easier:
We are also working closely with selected partners who are going down this route, and will consider working with others on a case-by-case basis.