Yes. Bill Gates once went to eastern Europe and gave a rah rah speech, where
he railed against piracy. Someone reminded him afterwards that many of the
programmers in the room got their start on pirated copies of Windows and now
work for Microsoft. He was in effect shooting himself in the foot by
depriving young programmers of access to Windows. I don't think that he has
made that speech since in a third world country.

Linux is much more prevalent in Europe in general and it is growing in the
BRIC countries (Brazil, Russia, India, China). I am not suggesting that it
is competing on an even foot with Windows, just that the numbers are skewed.
It is lower in the West and larger in the East.

Yes, the success stories are real. Wikpedia switched to Linux a few years
ago. They run Ubuntu. Yahoo runs Linux and BSD (Yahoomail). Google has
banned Microsoft products entirely, even on the desktop. IBM use Linux on
servers and the desktop. Even Hotmail used Sendmail at one time and
Microsoft recently was revealed to be running Apache servers. Shell runs
Linux servers. Most banks do because of its security. Even the US postal
service uses Linux to read addresses from envelopes. TiVo runs on Linux.
Paypal runs Linux. Zimbra uses open source.

see: http://www.aaxnet.com/design/linux2.html
http://en.wikipedia.org/wiki/Linux (server and embedded devices section)
http://www-03.ibm.com/linux/
www-01.ibm.com/software/webservers/httpservers/
http://mtechit.com/linux-biz/ (great list of companies that Hitachi works
with that use Linux)
http://www.bugzilla.org/installation-list/ (list of companies that use
Bugzilla and therefore must be running Linux because that is what Bugzilla
runs on)
http://curl.haxx.se/docs/companies.html (companies using curl)
x4.6times7.org/.../whouseslinux
http://www.linas.org/linux/
wiki.python.org/moin/OrganizationsUsingPython
http://www.mirabilis.ca/linux/linux-users.html
http://www.mysql.com/customers/
www.inforret.com/.../Perl_PHP_Programming.html
http://phpro.org/articles/Companies-Using-PHP.html
http://www.daniweb.com/news/story243967.html
www.huffingtonpost.com/.../...ft-win_n_595783.html
http://news.cnet.com/2100-1023-963937.html
www.theregister.co.uk/.../

Apache servers share of Internet traffic:
news.netcraft.com/.../...09_web_server_survey.html
www.pcworld.com/.../linux_is_on_the_rise_for_bu\
siness.html
http://news.cnet.com/2100-1001-275155.html (How Linux saved Amazon millions)
www.businessweek.com/.../windows-and-linux-servers-grow-at-uni\
x-s-expense.html
www.cyberciti.biz/.../...rvers-to-ubuntulinux.html
www.cyberciti.biz/.../...success-story-paypal.html
www.informationweek.com/.../showArticle.jhtml\
04300034
www.networkworld.com/.../ebay-use-joomla-open-source-glue
http://en.wikipedia.org/wiki/Embedded_Linux
en....pedia.org/.../List_of_devices_that_run_MontaVista_Linux
http://www.mvista.com/partner_portal/search/

I could go on all day, but this will give you an idea of the range of
companies and products. I am sure that I have forgotten as many as I have
remembered. It is a long list.