Today the Instance Adapter for Microsoft Dynamics CRM was published on GitHub as a public open source project using the MIT license. The current release listed there is a pre-release version for folks to test out and start contributing to if they would like to. The wiki on the GitHub site has the installation and configuration steps for the instance adapter listed as well.
The current version has not been changed from the previous version that was available last year.
It should be noted that this adapter IS NOT supported by Microsoft support. This is a community-based project and as such, it is supported via the developer community at the above GiHub site.