_(LMNL|http://www.lmnl.org/) is the Layered Markup and Annotation Language. It allows overlapping ranges, has structured annotations (attributes), namespaces, and layers. (Layers can be used to provide different views of the same document and add to other layers.)

It is similar to Ted Nelson's _(parallel markup|http://www.xml.com/pub/a/w3j/s3.nelson.html) (which was to be used in _(Xanadu)). (Actually, LMNL demonstrates a problem with parallel markup: <graphic src="crow.png"><link href="crow.xml">a crow</link></graphic> and <link href="crow.xml"><graphic src="crow.png">a crow</graphic></link> mean different things.)
