The exponential growth in the rate of scientific publication4 and increasing interdisciplinary nature of scientific progress27 makes it increasingly hard for scholars to keep up with the latest developments. Academic search engines, such as Google Scholar and Semantic Scholar, help scholars discover research papers. Techniques such as automated summarization help scholars triage research papers.5 But when it comes to actually reading research papers, the process, often based on a static PDF format, has remained largely unchanged for many decades. This is a problem because digesting technical research papers in their conventional formats is difficult.2

Scholarly publications are key to the transfer of knowledge from scholars to others. However, research papers are information-dense, and as the volume of the scientific literature grows, the need for new technology to support the reading process grows. In contrast to the process of finding papers, which has been transformed by Internet technology, the experience of reading research papers has changed little in decades. The PDF format for sharing research papers is widely used due to its portability, but it has significant downsides including: static content, poor accessibility for low-vision readers, and difficulty reading on mobile devices. This paper explores the question "Can recent advances in AI and HCI power intelligent, interactive, and accessible reading interfaces -- even for legacy PDFs?" We describe the Semantic Reader Project, a collaborative effort across multiple institutions to explore automatic creation of dynamic reading interfaces for research papers. Through this project, we've developed ten research prototype interfaces and conducted usability studies with more than 300 participants and real-world users showing improved reading experiences for scholars. We've also released a production reading interface for research papers that will incorporate the best features as they mature. We structure this paper around challenges scholars and the public face when reading research papers -- Discovery, Efficiency, Comprehension, Synthesis, and Accessibility -- and present an overview of our progress and remaining open challenges.