I just finished and released a beta build of my Spriter implementation that integrates into the FlatRedBall engine!
It supports linear interpolation only at the moment, but has full bone & sprite animation support.
Code can be found here: https://github.com/kainazzzo/flatredball-spriter
FlatRedBall has a development kit with a tool called Glue, which I have developed a plugin for as part of this project. The Glue tool is a project structure and code generation tool that adds a substantial productivity boost to game development. Glue has a plugin system, and in this particular plugin, I am able to define a custom type that Glue understands: SpriterObject and SpriterObjectSave. The save file handles deserializing the SCML format into object form, and has a conversion routine which converts the SCML objects into something that makes more sense for a runtime object.
The runtime library is extending the engine's built in PositionedObject (and derived type Sprite) to provide ScaledPositionedObject and ScaledSprite, which allows me to connect objects, give them relative values defined in Spriter, and based on the parent chain, absolute values are calculated. Due to this architecture, the main runtime object is scaleable, rotatable, and positionable within 3D space, with all animated child objects being positioned/scaled/rotated relative to the main SpriterObject.
I am still working on a tutorial, and there is much left to do in both the Spriter end of things (collisions & sound effects, as well as other interpolation types, multiple entity support), as well as on the FRB side. I am, however, extremely happy with it and wanted to share! http://www.gluevault.com/plug/79-spriter-integration-plugin