.NET Open Source Projects and Coding Guidelines
In my projects, we use a lot of open source libraries like Ninject, xUnit, Machine.Specifications, FluentAssertions, StyleCop, Moq, statLight, AgUnit and of course the project I lead myself: bbv.Common.
These projects are really cool. But sometimes of course, we need something that they do not (yet) provide. Like adding Machine.Specification support in FluentAssertions or a faster runner for xUnit unit tests under silverlight with AgUnit and statLight.
Therfore, we download the source code and try to contribute the features we need. And we try to follow the coding style of the existing code so that the project owners are willing to merge our changes into their code base. But this is almost impossible!

