[Freetype] Freetype: What are various modules...?

[Pedriana, Paul]

Freetype 2.04's ftmodule.h has this:

   FT_USE_MODULE(autohint_module_class)
   FT_USE_MODULE(cff_driver_class)
   FT_USE_MODULE(t1cid_driver_class)
   FT_USE_MODULE(pcf_driver_class)
   FT_USE_MODULE(psaux_module_class)
   FT_USE_MODULE(psnames_module_class)
   FT_USE_MODULE(ft_raster1_renderer_class)
   FT_USE_MODULE(sfnt_module_class)
   FT_USE_MODULE(ft_smooth_renderer_class)
   FT_USE_MODULE(tt_driver_class)
   FT_USE_MODULE(t1_driver_class)
   FT_USE_MODULE(winfnt_driver_class)

Now I understand how the mechnanism of dynamic drivers 
works, but I don't know what each of the drivers 
above does. In looking at the code for each of these 
drivers there is usually little or no documentation 
as to what it actually is. And the seemingly cryptic 
prefixes like 't1cid' don't help unless you already 
know what 't1cid' means.

So what are each of these drivers? I basically want
to be able to pretty much pare down the drivers so 
that Truetype and OpenType are the only drivers present,
as I only need to support these right now and can't 
spare the space for the code for other drivers. A little
documentation (like maybe 3 lines of comments) that 
explains what each one does and why you might need it 
would be useful.

Thanks.