PerfectIt is international. It works with all of the above. PerfectIt won't duplicate the functions of a spelling checker, but it will spot inconsistencies in language. So, for example, if you're using PerfectIt in its default mode then it won't correct 'organise' or 'organize'. However, if a document uses both 'organise' and 'organize', then PerfectIt will suggest that this is likely to be an error because the spelling is inconsistent. In addition, you can set PerfectIt to enforce the international spelling preferences of your choice. PerfectIt includes style sheets for UK, US, Canadian and Australian spelling preferences. So if you select the style sheet for 'US Spelling', PerfectIt will look for any words that need to be switched to US spelling. For example, with the 'US Spelling' style sheet turned on, PerfectIt will find all instances of 'organise' and suggest 'organize'.