microsoft office xml format schema references

[yaktur]

I am working on a Google docs like project so I will convert the pptx,xlsx and docx files formats to html5 files.Now I understand how to unzip the files and open each folder and I know the role of each file. but I need the xml schema of the document.xml file, what each tag and each attribute means.I have this xml spreadsheet reference from msdn but I need the similar links and descriptions for office 2007 and 2010 for excel,word and powerpoint.also I have the full schema of the pptx format here but I don't understand how to use it.