We're in the process of migrating our free ebook collection over to Penflip, an online, Git-based collaborative authoring and publishing tool. Matt Penny has taken the lead in converting our Word documents to the Markdown syntax used by Penflip, and as you can see on our ebooks page, most of the titles now have an initial version in Penflip.
One neat thing about Penflip is that anyone can register for a free account, fork one of our projects, and make their own modifications. You can then submit your changes back to the master branch, so we can incorporate your changes into the ebook. This will make it easy for everyone in the community to suggest new content, offer corrections, and so on. I encourage you to help out - right now, you may simply notice some flaws from the semi-automated and fully hellish Markdown conversion, and we'd love your assistance in correcting those.
Penflip also supports on-demand downloads of each ebook in a variety of common formats, including EPUB, PDF, and more. That means you'll always be able to grab the latest version of your favorite ebook. We've not yet migrated the source code that goes with some of the ebooks; the plan is to move those into our GitHub repo over the next week.
Penflip will be enabling the next generation of our ebooks, including a massive new DSC title I plan to begin working on in 2015.
Thanks for any help you can provide, and I hope you continue to find the ebooks helpful!