Since https://issues.apache.org/jira/browse/LEGAL-117 was approved, (some) dictionaries will be bundled with Apache OpenOffice 3.4.
A list of the dictionaries in OpenOffice.org 3.4 beta sources, their last revision in the Apache SVN (they were moved out of the main tree in revision 1209017 due to licensing issues), and the download URL for the upstream source follows.
TODO: Complete with Thesaurus/Hyphenation information, possibly with licenses, and complete the download links.
Note: the definitive list of the bundled writing aids is now in the extensions.lst file.