Norm Walsh has published a new DocBook NG release: "Hard Cider"

DocBook NG is a preview of DocBook V5.0 using the RelaxNG schema.

Details are available at http://norman.walsh.name/2005/01/18/hardcider and the schema is available at http://docbook.org/docbook-ng/hardcider/index.html.

Norm has also created a DTD version so folks with DTD-based validating editors can try it out.

From Norm's post:

In addition to the DTD, there are a number user-visible changes in the “Hard Cider” release:

• Allow <colophon> at the end of an <article>, RFE #1070458.

• Allow navigation components (<index>, <glossary>, etc.) at the end of sections.

• Allow xml:space (with the value “preserve”) on verbatim environments.

• Make <revnumber> optional in <revision>, RFE #1055480.

• Added “protocol” to the list of class values on <systemitem>.

• Add <citation> and <citetitle> to <attribution>.

• Added <alt> and <annotation>.

• Added rowheader to <table> and <informaltable>.

• Made <title> required on <preface>. It always should have been.

• Added <contractsponsor>, <contractnum>, and <mediaobject> to the content of <info>.

• Allow text where a proper date used to be required (<pubdate> and friends).

• Allow endterm on <link>.

• Allow <refsection> as a “start” element.

• Allow <initializer> in <paramdef>.

Most of these changes make DocBook NG more compatible with DocBook V4.x.

The Simplified DocBook NG release is still at the "Bourbon" version. I mentioned to Norm at XML 2004 that I'd like to take a stab at updating it, so I'll try to get some spare time to go and sample some Cider!

I'm very excited with the direction of DocBook v5.0 since it's using RelaxNG. The hard part is getting Relax NG adopted and supported out there. The best editor I've used with Relax NG support is Oxygen. Most of the projects I'm on are also "standardized" on W3C schema, so getting Relax NG accepted is a tough battle...