Murasaki is an EPUB reader application that has simple user interfaces and various features (CANNOT open DRM-encrypted EPUBs)
Scrolling - Murasaki is a scroll-based reader like usual web browers, not a page flip-based reader like iBooks.
Pagination View Mode (horizontal writing mode only) - Murasaki supports the pagination view mode. This is a hybrid view mode which has both a free scrolling and a snapping to column (horizontal writing mode only).
Swipe Navigation - Murasaki supports two-finger swipe gesture to move between contents (Mac OS X 10.7+). To read through an EPUB, use scroll and swipe gestures on trackpad.
Multi Windows - Murasaki can open different EPUBs in multiple windows. Moreover Murasaki can open different parts of one EPUB in multiple windows at once.
Popover - By opening a link in a popover, you can check a related page, footnote, and so on quickly without moving page (Mac OS X 10.7+).
Image Panel - By opening images in panels, you can read through text with reference to these images.
Searching - You can search a word that is contained in a EPUB.
Bookmarking - You can bookmark, and can refer these pages later.
Full Screen - By entering full screen mode, you can view the EPUB contents in full screen (Mac OS X 10.7+).
User Style Sheet - Murasaki can apply user style sheets.
Popover Dictionary - You can look up a word in popover dictionary.
Spotlight / Quick Look - Murasaki includes Spotlight and Quick Look plug-ins for EPUB. You can search and preview EPUBs in Finder
What's new in Murasaki
Implemented a sidebar context menu. To show it, right-click or control-click at sidebar.
You can open a section in new window from sidebar
You can expand/collapse all sections of sidebar
Implemented a Combined Contents Window. To open it, choose "File" -> "Combine All Contents and Open in Window"
You can select, copy, print all contents within an EPUB at once