The Layered Markup and Annotation Language (LMNL), introduced by Piez and Tennison at Extreme in 2002, differs significantly from XML/SGML by allowing elements to overlap and by allowing structured annotations within start and end tags. After brief initial development, LMNL has seen no widespread adoption, and few LMNL-specific tools or applications exist. Does LMNL matter or has it only curiosity value? From developing Limner (a prototype web resource for creating, storing, manipulating, and representing LMNL markup), the author has concluded that LMNL has great significance for markup theory and data models; its popular “success” is irrelevant. LMNL’s strongest challenge comes, not from element overlap as might be expected, but from its core concept of layers. Limner “stress tests ”LMNL’s layer model and shows how LMNL offers a fresh perspective on some current theoretical debates in which the word “LMNL” has never appeared.
But see the author package.