Linux in 3D
An AC sent in this link about Linux use in the world of special effects and animation. There are one or two errors in the story that make it clear the writer isn't that familiar with Linux, but it's still a good article about the digital effects world taking advantage of a free-beer operating system that runs on commodity hardware.
The 16 bit "hollywood" version of gimp has been available for about 2 years.
http://film.gimp.org/
The GEGL library that was written to support 16 bit images and it will be integrated into gimp 2.0.
To answer the above question about what 16 bits refers to, it means that an image has 16 bits per channel of color, 16 red, 16 blue, 16 green, equaling a total of 48 bits, but in film it is refered to as a 16 bit image.
We have to render all our images out in the 16 bit format(although many get away with 8 bit images). Also all the texture we apply in cgi have to be 16 bit for film.