British English

I find it quite disturbing to have the program in US English.
It is not this English that I've learned at school and so it gives me bad habits and I frequently make typos now.
Could we have a standard British English (UK) language file in the future ?
Or is it something user contributed ?

There are no plans for a British English version. Language addons are primary provided so more users that are not familiar or comfortable with English are able to use the product.

Are you based in America, then?
If you are not, you could replace US English with UK English as it is more standard and I guess the one that's taught worldwide.
What do you think?

I was taught UK English in school, but am fine using the US English version. If there is support for an UK-English language pack, however, I would be happy to create one for use in SmartFTP.

Can you name one or two items specifically that you find difference between UK-English and the version on SmartFTP?