For the formal, citable documentation for ACE we have submitted a summary article to Quaternary Geochronology. The reviews are back, and a comment that both reviewers made was ‘Which version number is ACE?’ This is a good question, and one we don’t have a good answer for.
The problem is that ACE is an open source development environment, which means that if you don’t like the way we have implemented something you can easily go to the source directory and change it. For the foreseeable future we expect to be doing most of the development (some exciting things in the pipeline!) but that shouldn’t stop anyone else from changing the code.
In this way, any change to the code should be considered a different version, and more importantly, if we change the code one way and someone else changes the code another, we have a version fork. At the moment we are taking a ‘wait and see’ approach to how to resolve this, but are open to suggestions. We imagine that at some time towards the end of 2009 we will release an ‘official’ version of ACE, which will reflect exactly what is written in the article. From that point forwards, we will probably note updates on the website as they occur. Is that reasonable?