filters.c             # pod (except experimental)
font.c                # pod
gif.c                 # pod
image.c               # pod
iolayer.c             # pod
pnm.c                 # pod
tiff.c                # pod

jpeg.c                # comments

conv.c                # minor comments
datatypes.c           # minor comments
draw.c                # minor comments
gaussian.c            # minor comments
png.c                 # minor comments
raw.c                 # minor comments 
regmach.c             # minor comments
trans2.c              # minor comments
dynaload.c            # minor comments

io.c                  # no comments
feat.c                # no comments
log.c                 # no comments
stackmach.c           # no comments

quant.c               # comments, lots of changing code

=====================

Iolayer todo list:
Format Read/Write
gif:    O    O
jpeg:   X    X
png:    X    X
raw:    X    X
tiff:   X    X
pnm:    X    X