support for the EPUB file type.

I use YACReader a lot on a daily basis and I mainly use it to read comics/manga (which i read in CBZ file format) but I also sometimes use it to read Light Novels, which come in pdf or epub format. epub is generally higher quality, so I was wondering if it would be difficult for epub support to be implemented any time in the future.

This has been considered many times, something in the TODO list, there are no warranties that it will happen though

There are publishers, who distribute comics as EPub. Many examples are to be found in the HumbleBundle sales.

It's not a question of epub availability. YACReader, like many other open source projects is a volunteer project with limited manpower, so we have to choose our battles wisely. We have discussed how to add epub support, but this is a mid to major project as YACReader is currently only able to display images whereas supporting epub basically would mean giving it capabilities that would be very close to being a full-featured Webbrowser.