To the uninitiated, an open directory looks broken. It is the raw file system of a web server, exposed to the public eye. The design is accidental; it is simply what a web server displays when the administrator hasn't placed an index.html file to hide the contents.
The "Index of EPUB Books Updated" page is a specific sub-genre of this phenomenon. These directories are often maintained by bots—scripts that scour Usenet newsgroups, IRC channels, and private torrent trackers, automatically downloading new ebook releases and dumping them into a folder.
The result is a chaotic museum of literary intent. Scrolling down the page, you see the raw data of reading habits. A high-resolution scan of The New Yorker’s latest issue sits next to a self-published vampire romance from 2014, which sits above a PDF of a university textbook on thermodynamics. index of epub books updated
The "Updated" tag in the title is the hook. It signifies that this isn't a dead archive, a graveyard of broken links from the GeoCities era. It means the bot is still running. The server is alive. Someone, somewhere, is feeding the machine.
Why rely on someone else’s server? You can create your own updated index using open-source tools. To the uninitiated, an open directory looks broken
Metadata updates
File fixes
Tagging / categorization
Indexing / search