To a point where your program won't understand/be able to edit a simple document created by Microsoft tools. In some cases, you'll see an embedded binary blob t

To a point where your program won't understand/be able to edit a simple document created by Microsoft tools. In some cases, you'll see an embedded binary blob that's actually an ActiveX executable in an OLE container. Here's some classic rants: https://www.tbray.org/ongoing/When/200x/2008/03/02/On-OOXML https://www.tbray.org/ongoing/When/200x/2008/03/02/On-OOXML https://ooxmlisdefectivebydesign.blogspot.com/ https://ooxmlisdefectivebydesign.blogspot.com/ http://www.groklaw.net/article.php?story=20070123071154671#Ecma_376_relies_on_undisclosed_information http://www.groklaw.net/article.php?story=20070123071154671#E... (especially in combination with: http://www.groklaw.net/article.php?story=20070123071154671#End-User_License_Agreements_.28EULAs.29_may_forbid_full_implementation http://www.groklaw.net/article.php?story=20070123071154671#E... )