The Document Foundation’s team told me that “StarWriter, the ancestor of the LibreOffice suite, was developed as proprietary software by Marco Börries, a German student, to write his high school final thesis.” He formed a company called Star Division to develop the software.
In 1999, Sun Microsystems bought Star Division for $73.5 million, changed the software’s name to OpenOffice.org, and released the code as open source.