[Typo3] List frontend users and groups on a webpage

[Pieter]

Hello all,

I would like to show (in the front end) a list of front end user groups 
and the members in each group.  Something like:

Usergroup 1
 Member1 name, E-mail, ...
 Member3 name, E-mail, ...
 Member7 name, E-mail, ...
Usergroup 2
 Member3 name, E-mail, ...
 Member5 name, E-mail, ...
 Member10 name, E-mail, ...

A started on a PHP script (my first ever!) to do this.  However, now I 
wonder: is there an existing way in Typo3 to do this?  I took a look at 
the SelectPro extension but my output is too complex for SelectPro (I 
think). 

Any other way to do this?

Best regards,
Pieter