Konqueror web archive
The web browser Konqueror, part of the KDE project, includes an option in the toolbar to "Archive Web Page", a feature that was apparently originally added by Andreas Schlapbach in 2001. Using this prompts the user to select a location, after which the browser saves a file with the extension ".war", which is actually a gzipped TAR file (often given the extension ".tar.gz") containing each resource on the current page as a separate file, as well as the main page, as "index.html". (These were originally just regular TAR files.) The Webarchiver plugin was removed in 2019.