In a world where it is equally easy to apply for a job in Asia, Europe, US or most anywhere else, the available software to read documents is likely to vary greatly.
Unless specified, what format(s) does one use to send digital information to someone, for example the HR department, when you have no idea what they can open?
LibreOffice, Microsoft Office, PDF, more than one of them, or something completely different?
I send PDFs (after all the name stands for Portable Document Format).
This has the added benefit that most recruiters (if you are using them) will not edit and change the CV.
A close second is Microsoft Office, this format can be read using Open/Libre Office, so offers most compatibility.
Another option is to have your CV online, on your server (or a trusted server) in HTML and simply point to it.
My main recommendation is to prepare your resume in multiple formats. I'd also recommend that one of the formats be plain text, and that you should use plain text for electronic submission.
Almost by definition, everybody can read HTML. PDF is a good choice too, as many readers are freely available, and it preserves formatting well. However, once you submit a resume you have no control over how it is processed. It might be printed out or faxed and then scanned and OCR'd. Somebody might decide to scrape the text out of whatever format you provide, or cut and paste just the text. I've received emails with horribly mangled text that was somehow derived from the nicely formatted document the candidate had submitted. For electronic submission, plain text is the least likely to be mangled in transit.
If you prefer something like HTML, MS Word, or PDF, use as little formatting as possible. It's quite likely that the fancy fonts, boldface, and italics you've chosen won't survive by the time the document reaches the eventual reader. Use simple headings and use lots of whitespace to separate headings and paragraphs. Also, avoid multiple columns or inset text. If any text is cut-and-pasted, it might interleave text from the different columns when it's pasted. This will leave the result all but unintelligible. Worse, most people along the chain from you to the eventual reader won't notice and probably don't care that much about the fidelity of what they pass along.
As someone who reads resumes and interviews candidates, I'm aware of all the formatting pitfalls and try to look past these issues. However, I suspect others are much less forgiving, and so malformatting will reflect badly on you. If formatting is bad enough, it'll make your resume too hard to read, and they'll just ignore it.
Bottom line: keep formatting as simple as possible.
I would suggest to have multiple formats to be prepared in the given order below. Also, try to include the web presence elements in your resume.
1) Start with a pdf format. It is very convenient format.
2) Another copy in MS Word format, preferably with .docx extension. Having docx extension will allow to access it through Open Office software, which is Free.
3) Create your resume online. (for ex: LinkedIn will work fine). Other online community/website where you might be involved into the project are also welcomed to be listed. Displaying web presence is a good sign that you are involved and up to date on subject matters concerning your business area.
