As with researching the best publisher for your print book, you will want to research which digital publishing platform is most suitable for your project. Which platform publishes in your subject area? Which have strong endorsements from current authors? Which workflow seems most suitable for your project? Which editors are most clear and communicative? How customizable is the platform to your project?
Keep in mind that some platforms, including PubPub, Fulcrum, and Manifold, are available for use by any publisher who applies. Others are specific to the press that created them. If the press that’s right for your project doesn’t have its own digital platform, ask your editor about using one of the platforms available to all publishers.