docx4j 是一個開源的(Apache許可證v2)Java函式庫，專門用來創建、編輯和儲存打包 Microsoft Open XML文檔（包括Word docx, Powerpoint pptx和Excel xlsx）。docx4j最初是由Plutext Pty Ltd於2008年創建。docx4j與微軟的OpenXML SDK類似，但是是面向Java的。它使用JAXB在記憶體中創建Java物件。它的功能強大，對於支援的文檔的格式，你可以用docx4j做出你想要的效果。
特色功能
- 打開已存在的docx/pptx/xlsx(從檔案系統, SMB/CIFS, 使用VFS從WebDAV等)
- 創建新的docx文檔
- 用程式來處理docx文檔
- CustomXML綁定(使用OpenDoPE外掛程式來處理重複綁定和條件綁定)
- 將檔儲存成HTML或PDF
- Diff/比較文檔、段落
- 導入二進位文檔(使用Apache POI的HWPF)
- 處理Word 2007的xmlPackage(pkg)格式
- 將docx保存成docx(壓縮格式)或者JCR（未壓縮格式）
- 字體支援（字型替代，使用文檔中嵌入的任何字體）
同時，需花時間理解JAXB和Open XML檔結構。可以使用線上的webapp查看docx/xlsx/pptx的檔結構，或者下載本地的應用Word AddIn來查看docx的檔結構。
| docx4j | Docx4j Enterprise Edition | |
| 100% open source OpenXML in Java, powered by JAXB | ||
| docx4j | V | V |
| pptx4j | V | V |
| xlsx4j | V | V |
| Key open source features - processing | ||
| content manipulation via JAXB | V | V |
| template variable processing | V | V |
| docx OpenDoPE conditions/repeats | V | V |
| docx MERGEFIELD (mailmerge) processing | V | V |
| Key open source features - importing | ||
| XML data binding (including images) | V | V |
| XHTML to docx | via optional LGPL2 jar | via optional LGPL2 jar |
| XHTML altChunk to docx (no need for Word) | via optional LGPL2 jar | via optional LGPL2 jar |
| RTF and binary .doc to docx (using Microsoft Word driven by documents4j) | V | V |
| Key open source features - export formats | ||
| docx to XHTML | V | V |
| docx to PDF (3 ways) | V | V |
| Licensing | ||
| License Type | Open source (Apache v2) | Commercial (source code available) |
| Enterprise Edition additional components | ||
| docx "MergeDocx" append/concatenate | - | V |
| docx altChunk merged as native content (no need for Word) | - | V |
| docx: file embedding (OLE) in docx | - | V |
| docx: digital signatures | - | V |
| pptx "MergePptx" append/concatenate | - | V |
| pptx: file embedding (OLE) in pptx | - | V |
| pptx: digital signatures | - | V |
| xlsx: file embedding (OLE) in xlsx | - | V |
| xlsx: digital signatures | - | V |
| Support features | ||
| community forums, StackOverflow | V | V |
| OpenXML documentation | V | V |
| super useful code generation (webapp or Word AddIn) | V | V |
| dedicated support team | - | V |
| proactive technical guidance | - | V |
| product roadmap input | - | V |
| release fast track | - | V |
docx4j for JAXB 3.0 and Java 11+