They would still have to maintain it, but they wouldn't need to add features. If they coded it well enough in the first place, that could be one person putting in 8 hours a month on the highest-priority issues in the backlog.
EPUB is a container format. It's basically an encapsulated multi-page website with some metadata. The marginal effort for a web browser is unpacking the files with a ZIP library and deciding how going from chapter001.html to chapter002.html works inside the existing UI. If you don't want to think much about the latter, render each page exactly as if it were downloaded from an online website, and use the forward and back buttons to step along the built in reading order.
I actually wonder why all web browsers don't support it natively.
EPUB is a container format. It's basically an encapsulated multi-page website with some metadata. The marginal effort for a web browser is unpacking the files with a ZIP library and deciding how going from chapter001.html to chapter002.html works inside the existing UI. If you don't want to think much about the latter, render each page exactly as if it were downloaded from an online website, and use the forward and back buttons to step along the built in reading order.
I actually wonder why all web browsers don't support it natively.