Around the time OpenIG 3.0.0 released back in August, we decided that the introductory part of the main guide left much up to the reader. Indeed, it introduced all the concepts, but you had to play with OpenIG for a while until those concepts would sink in.
For those of you trying the nightly builds, notice that since then the aim has been to simplify the draft of the next Guide to OpenIG. Thanks to Christophe, Guillaume, Jean-Charles, Ludo, Matt, Simon, Violette, Warren, and all of you who have offered your suggestions and pointed out parts that needed attention.
Now the guide starts with a short chapter on Understanding OpenIG. That chapter covers the main concepts that help you get started: the Exchange that encapsulates the HTTP request and the response as well as state information, the configuration including routes, how Filters and Handlers are chained together and how the Exchange flows through a chain.
The rest of the guide aims to be hands-on & practical. From the Getting Started chapter that should have you protecting your first app in a few minutes, through Installation in Detail and a series of tutorial chapters and configuration templates, to scripting and troubleshooting, you pick up the ideas a few at a time while seeing OpenIG in action.
Once you feel pretty confident that you understand how OpenIG works, to get all the details or to find just the right tool for a particular job you can check out the draft Reference.
Please feel welcome to log issues against these and all of the docs that we are working on.