Hello,

.abc , for alembic, is an interchange format for geometry and particles (point cloud).

For animation data, .abc use point cache, a little bit like .mdd. So there is no rig transfer, only vertex position are stored per frame (or sub-frame).
So it works whatever the kind of transformation you are doing. (like cloth simulation).

Topology, poly count can change from frame to frame, so you can store fluid mesh simulation too.

.abc can also store an infinite (well I don't know if there is a limit) amount of vertex channel data. vertex colors, vectors, uv's ...
Target platform are supposed to have tools to extract this data. An application is, for example, to shade a mesh (vertex shading) based on vertex velocity.
(very handy to create white water shading from fluid simulation).

For more technical information :

http://www.alembic.io/