Started my work to try and get a working build system for Cocoon 2.1.12 + FOP + eXist, based on RVDB's Ant script:

• First I had to get my head around Ant, which I haven't really used before. It isn't so complicated, but there's stuff I have to learn.
• I downloaded the FOP 1.0 stable release, and built it (with Ant), which is straightforward.
• I got the latest Saxon, in anticipation of using it for the XSLT in Ant tasks, and incorporating it into the Cocoon build. There's also a saxon9-ant.jar, which can be used for Ant tasks. RVDB's script doesn't use this; he relies on Saxon being on the classpath, and sets up his Ant task some other way, but I think I'll try to follow this explanation (the part on creating a <taskdef> with saxon9-ant.jar).
• I've downloaded a Cocoon 2.1.12 branch nightly, but I should really set this up through SVN so I can check out a new copy whenever we build; we do want to be able to include Cocoon bugfixes as well as those for eXist.
• I'm now working through and modifying RVDB's script, to make sure I understand everything -- how Ant works, as well as what modifications and patches he's doing. Ours will differ slightly. His documentation on how to build in FOP will have to be merged into the build script too, and that has a duplicate item in its task list; I'm not sure whether it's just a dupe or should be something else; I've written to check.