[pcwalton]

> And the result of a raster job is then coordinates in the Atlas?

Yes.

> Sorry if I wasn't clear; I was trying to understand whether the library or the application is managing the Atlas. Sounds like the library.

The library manages the atlas, because it uses a particular packing algorithm that maximizes the performance of the accumulation step (by increasing parallelism) when rasterizing many glyphs at once.