The XML dumps are the most compact and sustainable format in the mid term (let's say decades). https://meta.wikimedia.org/wiki/Mirroring_Wikimedia_project_XML_d

The XML dumps are the most compact and sustainable format in the mid term (let's say decades). https://meta.wikimedia.org/wiki/Mirroring_Wikimedia_project_XML_dumps https://meta.wikimedia.org/wiki/Mirroring_Wikimedia_project_... ZIM might be able to survive longer (centuries?) as probably the future will still need some HTML parser, while wikitext parsers or PHP might be long dead, who knows.