here's another treatise from a while ago by maxim shemanarev, author of the AGG library:

http://www.antigrain.com/research/font_rasterization/

edit: sorry i missed skittlebrau's mention of this, regardless, maxim has a lot of interesting articles on his site if you are interested in geometry rasterization

AGG really pushed the envelope, it's a shame that Maxim has seemed to have vanished off the face of the earth. Cairo has a different focus and I wonder if it will ever get to the same level of control and performance, given that it tries to target many different backends.

was surprised to see no mention of:

http://www.gnu.org/s/hello/manual/libc/Obstacks.html

seems like a very similar concept / means to an end?