MkTags is a simple Perl application that lets you edit the tags in a Matroska file. It can be used with WebM files as well, since this format is based on a profile of Matroska. It supports most of what’s in the official tag specifications. There is no fancy GUI; it simply launches a text editor. It could be viewed as a simplification of the XML that MKVToolNix uses, hence it is relatively open‐ended.