Knowledge portals are a method to provide integrated access to users of multiple systems through a single-entry point. A large body of literature exists on knowledge portals; however, the only published literature reviews are outdated, as they only cover material prior to the 21st century. The purpose of this article is to present review on some major papers about knowledge portals that were published from 2000-2017. The review takes a holistic perspective based on systems development life cycle to critique the literature and identifies key challenges that enlighten future directions. Trends in the first decade of the 21st century include the desire to formalize and standardize a model of knowledge portals, while major challenges for the future include the need to maintain cybersecurity across users and platforms.