What are some alternatives?
When comparing Readymag and SPIP, you can also consider the following products
MadCap Flare - Documentation for Any Audience, Language or Format
Zmags - Zmags provides solutions create and publish web experiences instantly.
FlippingBook - Make professional mobile-ready flip book from any document. Get trusted solution and impress your audience with quality digital publishing.
Yumpu.com - Yumpu.
PageSuite - PageSuite offers cross-platform digital publishing solutions.
Visiolink - Visiolink offers digital publishing solutions for newspapers and magazines.