One of the biggest problems in many open source projects is the lack of proper documentation. This is a shame because there is no point in implementing a thousand features if no one knows about them. The Gallio development team was very aware of this issue, so documentation was given a high priority from the beginning of the project. The API reference documentation, which is automatically generated from the source code, was the first sign of this concern, but the team knew users need more: they need a guide to show them how to use the multiple features, the runners and so on under different scenarios. So the idea of writing a book was there from the beginning, in our wishlist, but we knew it was a big task so it was postponed.