To my knowledge, there are two quality programs that can be used to produce illustrated, hyperlinked, and nicely formatted and organized eBooks: TreePad and Adobe. Both also offer free reader versions, so one is not forced to buy the programs in order to access their output files, which can then be shared freely, such as the eBook that you are currently enjoying.
My choice for TreePad has already been accounted for on MieNet, so I won't repeat it now (it's easily accessible here).
Having mentioned TreePad beyond its free Viewer (reader) in the Foreword, I feel I should offer you a bird's eye view of the TreePad line of programs, lest you might feel at a loss among so many choices. As a long-time user, I happen to have used them all, except for TreePad Asia and TreePad X Enterprise Multi-user.
I'll first refer to the shareware versions. But I should first mention some common characteristics to all TreePad's, whether shareware or freeware: they are all super simple to install and uninstall, and just as easy and intuitive to use. Moreover, they are such small programs that they can all be run from a disquette.
Beyond the overview that follows, meant to prevent that you should feel at a loss amongst the many different versions of TreePad available, you can of course find a lot more information about the entire TreePad line of programs at the . There, you'll also find a sign-up box for a that you can subscribe to, in order to be informed of news regarding any of the many TreePad's. I've been receiving these mailings for years now and can guarantee that you run no risk of spam, when you subscribe.
Last, but not least, here is my final observation. Just in case you may be wondering...this is not paid advertisement from TreePad! I'm just a very, very fond user of this program. For years now, I have considered TreePad the most useful software that I have installed in my computers! And it is so incredibly affordable and useful, not to mention its quality, that I feel I should support it, as a way to help ensure that I can continue counting on and its development, as I have so far, for many, many more years to come. Other than that, good things, I believe, should be shared.