Publisher to PDF is a free application, which allows users to convert Microsoft Publisher PUB files into the PDF format. There are no restrictions on the size of the files that can be converted and in most cases, the layout will be retained exactly. With that being said, one major drawback is the conversion time, with the free version of the software taking at least an hour to actually complete the process. To speed this conversion time up, users are required to upgrade to the paid 'Pro' version.