New c/5 diagonal technology
In September 2010, Matthias Merzenich found a new c/5 diagonal spaceship, with a minimum population of 58 cells. By this metric, it is the smallest known c/5 spaceship. This spaceship is wide and shallow, by contrast with Nicolay Beluchenko's long, thin c/5 spaceship (the previous smallest).
More importantly, it has an arrangement of accessible sparks, which can be used to perturb objects. Specifically, it can interact with a glider chasing from behind, and a further ship can modify the resulting prominence to produce another forward-directed glider. Another pair of spaceships in a reflected arrangement can repeat the reaction, restoring the glider to its original lane and timing. This facilitates a dirty puffer with period 1450.
Based on this design, Matthias proceeded to engineer a clean c/5 rake, with period 1585 (View image | Download file). It contains two equidistant gliders circulating in a p3170 base loop. The gliders are replicated and positioned to destroy the debris created by the puffer engine.
UPDATE: Matthias has, the day after this article was published, found a c/5 tubstretcher and tubeater!