Sci-Hub is a shadow library website that allows unrestricted access to millions of research papers and books by circumventing publishers' paywalls in various methods. Alexandra Elbakyan started Sci-Hub in Kazakhstan in 2011 in reaction to the exorbitant cost of research publications behind paywalls. The site has since then become a threat to academic publishing as well as the business models of several major publishers. It works by allowing users to download articles for free from the website's repository, which is built using Microsoft's Open Research Platform (ORe) software. When a user visits Sci-Hub, they are first shown a list of most-viewed articles. If there is an article that they want to read, they can click on it to be taken to a new page with just that one paper, which they can then download for free. There is also a button on this page that will take them to an options menu where they can select different ways to view the paper, such as in PDF or HTML format. There are two main problems with traditional academic journal publishing. The first is that it can be expensive. A study conducted in 2014 by the University of Illinois at Urbana-Champaign found that accessing the published literature requires up to $90 of annual spending on average, mostly due to publication costs. The second problem is that not everyone who needs access to important research findings can afford it.