Provide a document validator/fixer for testing/repairing XHTML validity of the pages

In an ideal world, all the users would need and use would be the wiki syntax. However, a lot of content writers think that they can use markup, often leading to invalid markup, or worse, broken layout. And some often blame the platform for this.

What would be nice to have (optional items, not all)

• validate on save: after saving, the engine validates the markup and reports errors, with an automatic cleanup, possibly using tidy
• scheduled/triggered validation for the whole wiki, reporting all errors in the wiki pages
• offline checking tool for the database