From the XML Prague tweets, I get the impression that SGML is a thing again in the markup community. Opinions?
[1]: https://twitter.com/search?f=tweets&vertical=default&q=%23xmlprague%20OR%20%40xmlprague
[2]: http://sgmljs.net/docs/html5-dtd-slides-wrapper.html
[3]: https://www.youtube.com/watch?v=jy-b4jeJSas&index=14&list=PLQpqh98e9RgUcEmbXmI6RolisQaIRw9dm