I've just released new minor versions of XMLUnit for Java and XMLUnit.NET. Both releases are improvements.
Changelog for XMLUnit for Java 2.8.4:
Changelog for XMLUnit.NET 2.9.1
improved comparison performance for documents with many siblings
based on a suggestion by @gerpres made in Java Issue xmlunit/#236
added a new FullDescription method to Diff that provides a string-representation of all differences - not just the first one like ToString does.
Based on Java PR xmlunit/#235 by @Boiarshinov
Right now there seem to be some issues with Sonatype's OSS Nexus (likely under heavy load) so it may take a bit longer than usual for the new Java artifacts to show up in Maven Central.