Are they needed ?

[Petur Kirke]

Please help a dummy !

The readme-install file says:

4)
Technically, at this point, MS4W is installed! However, as you may have noticed 
from the MS4W main index.html page, there are no applications running. What 
this means is that there are no Web applications like MapLab or Chameleon found 
within MS4W's Web-accessible directory, /ms4w/apps/. The MS4W-configured Web 
applications can be found on http://maptools.org/ms4w/index.phtml?
page=downloads.html as separate zip files.

My question is:
Do I need MapLab or Chameleon to run Mapserver ?
What are these programs for ?