Several months ago (when you see this post, at least another 3 months have passed), I was searching for an electronic edition of the classic book Visual Basic 6 Bible, and finally found it at Archive.org. However, not only did it take weeks to borrow, but also the finally downloaded ebook is a scanned and encrypted (with DRM protection) PDF file - which means it cannot be opened using any PDF reader other than the Adobe Digital Editions - the only book downloader & reader specified by Archive.org.

On many users' computer, it's probably that an EPUB (mobile-specific ebook format) reader is not installed at all. In that case, what we first think of is to convert it to the most commonly used and universal format for almost any device - PDF, therefore we still need some tool to help.

As ever the most common electronic document format, CHM features smooth running and convenient retrieval. While it's a pity that it does not support the popular features such as highlight, annotation and labeling. If there is no alternative PDF edition in hand, then we can use Atop CHM to PDF Converter to convert CHM format ebooks to PDF format.