List toolboxes currently in use by session

How can one list what features (toolboxes) are currently signed out for the current session?

Answer 1

[Joseph Cheng]

license('inuse')

will show the toolboxes checked out

[Andreas Goser]

Important to note is that

ver

as suggested below is only showing the installed products, not the used ones.

Answer 2

[Bastien Chardonnens]

The function

ver

will give you this information