Files in attic/** are scheduled for eventual deprecation, but in the meantime they are separated into their own folder to de-clutter the Drake source tree.

When #include-ing files from this subtree, omit the "attic/" portion of the path. (Similarly, headers or data that are installed from this tree also will omit the "attic/" path element in the installed location.)

Drake's original RigidBodyTree class and its related code lives here. The replacement implementation is MultibodyTree and its related code.

The name "attic" is inspried by the CVS source control system, e.g., https://docs.freebsd.org/info/cvs/cvs.info.Attic.html