When to Code a Source:
If you cannot find an existing source or you are looking to integrate a completely new application you could always make your own. Before you jump into coding however, it would be a a good idea to examine the source code of the sources available. Rather than starting from scratch, its often easier to tweak an existing program to your specific needs.
Two Ways To Go
DataTurbine provides a standard API through which to push and pull data. This API can be a bit overwhelming, so to get you started we wrote an abstracted interface that exposes the functionality most relevant to building a source.
Pick the interface you are most comfortable with: