Since OpenOffice 2.3 you do not need an X display for starting ooffice. However you may need the openoffice.org-headless package from your distribution. Since OpenOffice 2.4 nothing special is needed, running in headless mode does not require X.

For any older OpenOffice releases, remember that ooffice requires an X display, even when using it in headless mode. One solution is to use Xvfb to create a headless X display for ooffice.

http://www.oooforum.org/forum/viewtopic.phtml?t=11890
http://www.wonko.be/2008/01/09/running-openoffice-headless-on-debian
http://ward.vandewege.net/writings/200510auto_doc_conv/
http://www.artofsolving.com/node/10

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