The latest build instructions can be found under the Apache OpenOffice Building Guide and we are trying to improve the documentation continuously. If you run into trouble and find problems please let us know. We appreciate every kind of feedback that help us to improve the usability of our source releases. OpenOffice is a very huge piece of software with many external dependencies but these build requirements have to be collected only once.
Older build instructions are kept for convenience for users who still want to build older sources.
For the old build instructions for OpenOffice.org, go straight to AquaBuild.
If you're looking for information on how to build old versions of OpenOffice.org that still require X11 to run, head to Mac OS X Build Instructions (X11)