Get the text under the mouse ?

[Regatta <regatta gmail com>]

Hi everyone,

I saw a very nice program in my friend (windows box) , the program is
very simple, just move your mouse over any text and wait for a few
seconds and it will display a translation for the word and also it can
speak/spell the word

I am planning to "try" to make something like this based in GTK and
using dictd and Festival

So my first question to you guys, is there any program can do that :) ?

the second one, how to know where is the mouse now in the screen and
what is the text under it (at less let make it work with GTK application
then we can find something to do with the non-GTK application)