The Alt+Tab key combination is perhaps one of the most well-known keyboard shortcuts in Windows, with the only competitors for the throne being Ctrl+C and Ctrl+V. And no matter, whether you are used to alt-tabbing for working purposes or simply as a means of efficient undercover procrastination, unless you are a complete novice you probably have this skill at the level of basic instincts.
Unfortunately, there are cases where the instinct becomes inconvenient. Namely, whenever you use an application that displays multiple documents in separate tabs (like Firefox or Notepad++) or in separate child windows (like R), you are expected to use Ctrl+Tab rather than Alt+Tab to switch among documents. However, most of the time switching among documents is subjectively perceived as nothing essentially different than switching among programs, hence the fact that Alt+Tab won't work normally for that case is highly unintuitive. The typical case with me is that I would accidentally use Alt+Tab attempting to switch between the editor and console in R and unexpectedly find a completely different window in front of me, which is quite annoying.
Although I am pretty sure I am not the only one to experience this kind of frustration, it is surprising that there does not seem to be any easily available solution to this trivial issue known to google. Thus, considering that the whole problem can be solved to a fair extent by simply translating Alt keypresses into Ctrl in a smart way, I've made a smallish program that does exactly that.
I'm quite happy with the result and can't help sharing it with you.