We analyzed visualization paper keywords supplied for 4366 papers accepted to three main visualization conferences. We describe main keywords, topic areas, and 10-year historic trends from author-chosen keywords for papers published in the IEEE Visualization conference series (now called IEEE VIS) since 2004. Furthermore, we present the KeyVis Web application that allows visualization researchers to easily browse the 2600+ keywords used for IEEE VIS papers of the past 10 years, aiming at more informed and, hence, more effective keyword selections for future visualization publications and efficient search for related work.