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Consider this in a similar light: if you're a public speaker, charging an appearance fee and using a PowerPoint slide show in your presentation. By the clauses outlined above, you would have to give Microsoft a piece of your action.
Lest the above clauses seem too vague, the Apple EULA goes even further:
(Their bold-face, not mine.)
Read that paragraph slowly and carefully. Suppose that you spend the next several months writing and formatting your work into a specimen of shocking and brilliant prose. Then you submit it, only to find that for whatever reason, Apple rejects it. What rights is Apple claiming? Here it gets interesting. You can submit the work elsewhere, but not in the form in which it currently resides. First you must strip the document of all its markup language, reducing it to plain text, and then mark it up in another language such as the industry standard EPUB. The agreement states that Apple iBooks uses the EPUB format, but won't allow a 100% compatible export, even using the Save As (.iBooks, then rename the result to .EPUB). Depending upon the interpretation of the agreement, however, even this output might be deemed covered by the egregious clauses.
When we first heard of this new software, my co-author Peter Brawley and I greeted it with enthusiasm. Second and third readings of the EULA have pretty much dissipated our initial take. At this point, our advice to would-be iBooks authors is simple: read and re-read the EULA carefully, and when you are sufficiently dizzied by its language, have your lawyer read it too. And if you still want to walk into this feudal arrangement, we wish you the best of luck.