The process of pulling the book together happened in two phases: an incubation phase and a public phase. I initially gathered contributions from a smaller group of contributors, so as to prime the contributions with the bar set at a good level. They were invited or contacted me having heard of the project by word of mouth. When the project went public, via Twitter, conference mentions, InfoQ, lists, etc., contributions came in from a far wider range.
The incubation phase took around 6 months, and was relatively slow burn, slow accumulation of articles that I edited as they came in. The public phase lasted about two months, and was shorter than originally planned because the participation was larger than expected. I managed to keep up with the editing, but it was certainly more intense! Once the cut-off date was reached there was relatively little editing work to do, so the challenge was to make the selection and address other book-related issues.