Initial Release, not all configurations are tested extensively. Main testing has been around 2010, though unit tests are increasing and I am happy with the API and project structure now. From this point any API breaking changes will result in a minor version number shift until we hit 1.0.
I Recommend you use the NuGet packages to install as there are 4 packages which will automatically install the correct dll's.
Download the version which suites your needs. You should download the package which targets the lowest version of Office you are targeting. For example if you have some 2007 and some 2010 users of your add-in. Download the for 2007 package.
Read more at
http://jake.ginnivan.net/vsto-contrib/introductionhttp://jake.ginnivan.net/vsto-contrib/ribbon-factory