Kraken is a battle tested library for developing SharePoint applications that's been around since before 2010 and is used in many projects. This package includes libraries useful for developing sandbox solutions and SharePoint configurations with limited trust. Note that it is also included in SPFarmLibrary, so you don't need to reference it seperately.
See the version list below for details.
v0.2.4: AssemblyVersion compiler directives reversed to make v4.5/v15.0 the default and v3.5/v14 only when .NET 3.5 is set.
- SharePoint (>= 15.0.0)