Progressive Rendering in Network rendering like Maxwell
(http://support.nextlimit.com/display/maxwelldocs/Progressive+Rendering+Workflow)
Maxwell can be configured to allow the render servers to render a complete sequence at (n) passes -
For example (6,12,24)
The whole sequence will finish to render each file at 6 passes (at a low Sampling Level) and move to the next frame. When the whole sequence is complete it will then RESUME the render from 6 to 12 (does not need to re-render the already 6 passes) and save each, finally it will render the passes from 12 -24
In this way you can already use the sequence in compositing at a lower quality while the higher quality is in progress