Backwards compatibility depends on software companies. “Microsoft doesn’t want to support all of the quirks of their legacy formats forever. That just leads to bloated, fragile code, more expensive development and support costs. They would rather have clean, structured markup, like ODF.” ( accessed 27.11.2007).

As generations go by, the legacy formats will drop. It’s not certain that modern applications are fully backwards compatible anyway. “In researching this article, I tried to open some of my notes which were written in an old version of Word for Windows. Word 2007 refused to open them for “security” reasons and pointed me on a wild-goose chase of knowledge base articles describing obscure registry settings I would have to set to open old files. It is extremely frustrating how much you have to run in place just to keep where you were before with Microsoft’s products, where every recent release requires hacks, workarounds, and patches just to get to where you were before.” (Joel Spolsky,, accessed 27.11.2007).

Microsoft have dropped VBA for Macintosh versions of MS Office (same blog entry). “Word 2007 can open files created in all previous versions of Word, 1.0 through 2003. Word will open older documents in compatibility mode. You know this because at the top of the document “(Compatibility Mode)” appears next to the name of the file.” (Microsoft’s website: accessed 28.11.2007)