What is a .docx file?

Today someone sent me a MS Word file in an e-mail. Being a Linux user, I don't quite like working with MS-Office documents. However, I have accepted it as a reality of life. Also, Openoffice is now good enough to handle most MS-Office files.

The file I got today in mail had a .docx extension to it. I initially thought the sender had saved the file with wrong extension, but soon realized that Openoffice doesn't know how to open it. "file" command on the file says it is a zip file. Hmm... okay, let's unzip it. It contained a bunch of xml files among other things. I wasn't sure what was happening. The obvious next stop was google.

Google told me that .docx is an ooxml file, which is the latest standard for office documents being pushed by Microsoft. Openoffice doesn't support it yet, so there was no way (that I know of) to open it on my Linux. I booted to my Windows partition and showed the file to MS-Word. It too refused to open it. Hmm... some more googling revealed to me that the ooxml format is the default on newer MS-Office versions, whereas older versions don't support it. There is an update available from Microsoft that makes old versions of MS-Office handle ooxml files. The update was 26MB in size, so instead of pulling it down, I asked the sender to save the document in older MS-Word format and resend it.

A couple of things that surprise me are, a) MS-Office has been using ooxml format as the default for a while and I don't even know about it. b) Users of new MS-Office will typically save their files in new format because that is the default. That means all users of old versions will need to pull down this 26MB update to see these files. 26MB is not a very small size for low-bandwidth users.

I hope ODF benefits from all this.