I've been lucky enough to never have to actually develop ODF software for integration with Libre Office / MS Office, but from I've read, the specifications were

I've been lucky enough to never have to actually develop ODF software for integration with Libre Office / MS Office, but from I've read, the specifications were half-heartedly published, and it is now basically a game where developers have to figure out all the exceptions to the interfaces that are within Office. Some work-around that might have worked yesterday might not work after an update of Office (which happens every few weeks). Again, the cynical part of me assumes that MS employs full-time staff to ensure that Libre Office, Google Docs, and other apps that work with MS Office will never be even 95% compatible. And from my experience, even simple spreadsheets and formatted Word docs don't display properly when opened in Google Docs or Libre Office, and large, complex business docs with macros and esoteric formatting don't have a chance. There are a few developers in every place I've worked who use Libre Office because they're on Linux or refuse to pay for Office. And you can tell when they collaborate on a doc with MS Office users because it renders poorly when they send it back. It doesn't bother me, but I've seen how folks in management, marketing, etc. consider it unprofessional and assume the developer is just lazy or can't use Office well. The one silver lining is that Linux users can use Office 365 online for less complex docs; it's not a full replacement for offline versions, but it's a better alternative than Libre for those of us who believe it better to be compatible with others even at the cost of a 365 subscription.