This page is part of the FHIR Specification (v0.4.0: DSTU 2 Draft). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions
This page is a registry of the various places where support for implementations can be found.
In the first place, implementation questions - how do I do X? - should be asked on StackOverflow.com using the tag [hl7_fhir].
Stack Overflow Questions about FHIR.
Note that you should not use Stack Overflow to discuss specification design issues. This is a Stack Overflow rule - see guidance about this.
If your question is about why the specification is how it is, probably the best place to start is the FHIR wiki, which is the home for the FHIR development team. Active discussions are found on the FHIR email list. The development team hangs out on Skype, and you can ask to join the (busy) skype channel.
This general collection of links may also provide additional helpful information: