The ToRTF is a file format batch converter. It can convert office documents to a portable RTF file format:

*.doc - Microsoft Word 97-2002
*.doc, *wpd - WordPerfect 6.x/5.x
*.htm, *.html, *.htx, *.otm - HTML (on 2000/XP/x64)
*wri - Windows Write (on 2000/XP/x64)
*.docm, *.docx - Microsoft Word 2007 (additional download is required)
*.doc - Microsoft Word 6,95,97-2003 (additional download is required)
*.wps - Microsoft Works 8/8/7/6/5(2000)/4.x (additional download is required)
*.mcw,*.xls,*.pwi,*.wk*,etc - different documents supported by Microsoft Office 2003 (Microsoft Office 2003 installed is required)
Features
Selection files to convert using drag and drop, file selection, folder selection;
Can convert multiple files or folders;
Microsoft Office is not required for most file formats;
Command line support;
Fast multithreading convertion, optimized for dual-core CPU.

The license of this software is Free Trial Software, the price is $25, you can free download and get a free trial.