Interested in learning more on OPEN XML?

I recently got a query from a customer for information on Open XML development and compiled a couple of links so sharing here as well:

Good background on Open XML and link to technical preview:
https://blogs.msdn.com/erikaehrli/archive/2007/06/04/announcing-the-new-open-xml-object-model.aspx

2007 Office Document: Open XML Markup Explained (book download)
https://www.microsoft.com/downloads/details.aspx?FamilyID=6f264d0b-23e8-43fe-9f82-9ab627e5eaa3&DisplayLang=en

2007 Office Sample: Building Server-Side Document Generation Solutions Using the Open XML Object Model (Walkthrough)
https://www.microsoft.com/downloads/details.aspx?FamilyID=16efd28b-8825-4057-8ea6-076e9de1368d&DisplayLang=en