At http://www.primopdf.com/ I found a free program to convert almost every file into PDF. It's completely free. You can even download the source file (at the bottom of the page, "PrimoPDF Source") so I guess this program is completely free of any licenses.
Could you make this program portable? I know there is OpenOffice.org but it doesn't do the job as well as PrimoPDF (the PDF doesn't always look completely alike and/or the PDF gets to 4 times as big as with PrimoPDF).
Thanks!
There is a License and it isn't GPL. It's Freeware and permission would be required. While I could not find the License directly on the WWW site (even the Source Code ZIP surprisingly doesn't have a License text file in it), the installer has the License Agreement in the standard NSIS dialog.