Some of my spelling checking software failed to recognize the American spelling of the words "organize" and "realize" when a British English dictionary is being used. Curious, I looked up the British form of these words, "organise" and "realise" on oxforddictionaries.com and realize that it actually places heavy emphasis on the American spelling instead of the British one.
Upon further investigation, OED actually has this clarification which I quote:
Why does the OED spell verbs such as organize and recognize in this way?
The suffix -ize comes ultimately from the Greek verb stem -izein. In both English and French, many words with this ending have been adopted (usually via Latin), and many more have been invented by adding the suffix to existing words. In modern French the verb stem has become -iser, and this may have encouraged the use of -ise in English, especially in verbs that have reached English via French. The -ise spelling of verbs is now very common in British use, and Oxford dictionaries published in the UK generally show both forms where they are in use, but give -ize first as it reflects both the origin and the pronunciation more closely, while indicating that -ise is an allowable variant. Usage varies across the English-speaking world, so it is important to record both spellings where they exist. There are a number of verbs with only one accepted spelling – advise and capsize, for example. This is not just perverse: they have different etymologies. The important thing is that people should be consistent in the form they use in a given document.
Nevertheless, from the way things are being presented, it does give me the impression that the American spelling is given a higher priority in a dictionary that is prepared by a renowned British university. Are we moving towards Americanized spelling and more importantly, are the people of Britain moving towards Americanized spelling?