GITIM is an algorithm for the analysis for generic interfaces (planar, spherical, and also without any particular symmetry). It is a generalization of the ITIM algorithm, which was initially conceived to treat planar interfaces only.
GITIM analysis tools are provided for the GROMACS simulation package, in the form of a modified gromacs tool and of a stand-alone program.
GITIM makes use of alpha shapes - slightly modified to take into account excluded volume - to identify those atoms or molecules which lies at the interface between two phases/components. Once surface atoms are identified, you can analyze their properties, or compute intrinsic quantities (that is, removing the contribution of capillary waves at the interface), such as intrinsic density profiles.
The source code can be found at the GitHub pages of the project