How to get programmatically the currently active application?

Hi all, I want to develop a kind of automatic timetracking sw where every minute checks what is the currently active application. Is there any way to get it with Matlab? Any suggestion is appreciated

[Guillaume]

What do you call THE active application.

Bearing in my that all OSes that matlab runs on are multitasking OSes where there's never just one single executable running at a time.

[pietro]

For active application I mean the currently active application, the only one that it is not in background. For example matlab if you're programming in Matlab.