To celebrate 25 years of publication of International Journal of Wildland Fire, we have put together a virtual issue that includes some of the most-cited Research Papers we have published over the years. This virtual issue includes two papers from each five-year period, starting in 1991. One of these is the paper from each period that has received the most citations to date. To highlight the geographic scope of IJWF publications, the second paper is the most-cited paper where the lead author is from a different country than the highest-cited one. We have included only standard Research Papers. The Journal also publishes review papers, research notes, and other types of papers, which have not been included in this special 25th anniversary issue. Some of the review papers, in particular, are among the most highly-cited papers. A list of most-read papers and topical special issues can be viewed. We also note that the selection of ten papers in this virtual issue does not cover the full topical scope of IJWF, which in recent years, for example, has had an increased number of papers from Social Sciences and other emerging areas of wildland fire research. Additional information on the history and accomplishments of IJWF over the past 25 years is described in the foreword Twenty-five years of International Journal of Wildland Fire.