widmogrod/zf2-assetic-module — pull request #63 by rhysr (2013-04-20 20:45:53+00:00)
Title: get asset writer from service manager

Unless I'm doing something wrong, I've noticed that the assets get created on every page request which seems wasteful and it causes the file's modified time to change resulting in browsers not being able to benefit from 304 http responses using the Last-Modified header.
Whilst, this isn't a solution to that problem directly, it provides a hook to inject a new asset writer which can determine whether to actually write the asset.