Igor Wiedler has started up a new project that helps you combine "stacks" of middleware related to the HttpKernelInterface from Symfony as a sort of decorator to its base functionality - Stack.

In the post titled HttpKernel middlewares I brought up the idea of bringing rack middlewares to Symfony2. In order to solidify this effort I would like to announce a new project: Stack. Stack is a convention for composing HttpKernelInterface middlewares. The name and logo are based on the idea of building a stack of middleware layers, each of which handles a particular piece of logic. [...] The main goal of stack is to give the idea of "HttpKernel middlewares" a name, so that we can more easily talk about it.

There's a stackphp organization on Github that has the start of this set of middleware pieces including tools to help you build other features. The project is focused around the Symfony HttpKernelInterface because it was the simpler, more standardized option for now. He notes that there's no reason that, in the future, when things are more standardized it couldn't broaden out to PHP as a whole.