[unsafecast]

From the FAQ:

If a BookReader edition is available, you can read it instantly online by clicking the "Read in Browser" link. You're done! Borrowing books in other formats will require Adobe Digital Editions or ebook software that works with Adobe authentication. You can read this FAQ entry for information on other ebook software. An Adobe.com account which you can get

I must misunderstand something then. Is it not a choice between browser and adobe id?

[mekarpeles]

Readium LCP will be an alternative to adobe ADE.

[unsafecast]

Ah, so _will_ be. Thanks a lot, looking forward to it!