Just released, version 2.7.1 of docx4j is the first version of docx4j which is in Maven Central.
This article walks you through the process of installing Maven support in Eclipse, and then using that and a few lines of code to create a Word document which says "Hello Maven Central".
docx4j is an open source (Apache v2) library for creating, editing, and saving OpenXML “packages” - not just docx documents, but also pptx presentation, and xslx spreadsheets.
It is similar to Microsoft’s OpenXML SDK, but for Java rather than .NET. It uses JAXB to create the Java objects out of the OpenXML parts. See the 2.7.1 release announcement.