Processing Camera Raw files to JPEG, TIFF, or PPM formats is extremely time 
intensive. Utilizing multiple threads on multi-core systems can realize an 
increase of productivity and time savings of 60%.

The multiraw.c program allows the user to batch convert Camera Raw format files
in parallel using pthreads. The user may specify the number of threads to run,
or they may use the Auto Thread switch which will cause the software to
determine the appropriate number of threads based on the task requested.
By default, multiraw.c calls dcraw-m, which is included. If the user wishes
to use the unmodified dcraw program, it may be specified using the -o switch.

Use the -n switch to specify number of threads, or use -a to instruct the 
software to automatically determine the optimal number of threads to use 
depending on the commanded task.

multiraw uses dcraw-m, a modified version of dcraw which automatically 
rotates exported thumbnails and has a camera timezone offset adjustment
variable.

WWW:
https://dx.burplex.com/bin/multiraw.html
https://dx.burplex.com/bin/autorot.html
https://dx.burplex.com/bin/photohack.html