ArchiMate is the de facto standard for EA Modelling, as defined by The Open Group
Archi is the de facto reference implementation of the ArchiMate modelling language
Version 3.2 is the most current production version of the specification
Third party support is extensive, including players such as BizzDesign, Sparx, ABACUS, LeanIX, Ardoq, Visual Paradigm...
A standard XML-based interchange file format is defined, permitting model migration between competing tool vendors
And ArchiMate 4 is coming...
Challenges
Sometimes elements are duplicated across layers yet with different meanings (e.g. Business Service vs. Application Service vs. Technology Service)
Reliance on element colouring emerged as a way to help mitigate this -- yet the standard does not mandate a particular colour scheme (and some third party references deliberately choose non-familiar palettes)
As enterprise systems grow in complexity, it is not desireable to increase the size / complexity of the modelling language -- this is a trap that, say, UML has fallen into over time