Amazon Kindle devices may not support ePub files. But there are plenty of ways to consume ePub ebooks these days. You could always buy e-readers from Amazon’s competitors. Extensions such as EPUBReader let you read these types of books on your computer. This is a Firefox add-on that opens ePub files in Firefox. There is no need to download any additional software to get started.
EPUBReader downloads ePub content, makes some processing, and displays your file for your consumption. You could also use the open file option in Firefox to open and read ePub files on your machine. This ePub reader does not have too many bells and whistles. But it does handle this document format quite well. You can access all your ePub files using the ePub Catalog link.
You could always use your NOOK or iPad to read ePub e-books. But on your desktop machine, EPUBReader for Firefox is well worth trying.