As the API economy continues to evolve, one of the foundations is that there is enough network bandwidth between two different applications such that latency and state are never in issue. In practice, given the state of most wide area networks, there is not always as robust a connection in place as most developers would prefer.
Cloud computing is big right now, but the sheer number of options, and the lack of interoperability, can be an issue for developers. There are a number of projects that can reduce, or even eliminate, some of these problems by exposing the functionality of a number of cloud service providers through a consistent interface. Here is a list of 7 such projects.