Calibre
At first glance, it looked comprehensive and feature-rich. I wasn't thinking about DRM, but have a ton of books in both eReader and Kindle format, bought and paid for. Can't read any of them, can't change formats. I understand the philosophy, but aside from going to Gutenberg or Sacred Texts, etc., it's just not worth having another program on my system. I use Mobipocket, which works well enough for me to create Kindle books. I can't, however, read any of my eReader books on my Kindle handheld, having to use my PC based eReader Pro app. You would think by now the industry would have provided a fair and legal way to handle this, but market share and greed rule, I suppose. To be fair, Calibre is the best of what I've seen, but limited in usefulness for me personally.
