Recognition a pointed text

[git]

Some programs (StarDict, Lingvo 12) use this feature: when you point with mouse cursore some word on your display it shows translation of this word. It's very interesting how they get a translated word? Does somebody know answer for this question?

[TcM]

I never used such applets, but they either use the internet and connect to a remote server than can translate that word and the application shows you that word, or as far as I know even MS Office XP has a translate feature offline. So i bet that those programs use something like this, either one or another....