Our understanding of the past will, to a large extent, depend on our success with Web archiving. WADL 2015 brought together international leaders from industry, government, and academia, who are tackling this important challenge. This special issue includes summaries of twelve presentations on 24 June 2015. It is hoped that these works will stimulate other digital library (DL) and related investigations and efforts that will help ensure that broader and better archiving takes place, that more tools (beyond the excellent ones mentioned in these papers, that generally are freely available) become available, and that wider support develops to expand Web archiving.