Peter Mueller asked:
is there someone out there who has a list of the transitive
permutation groups of degree 12 (or even higher)?
There is. I've put a library with groups up to degree 15 (which are to be
added to the next version of GAP anyhow) in a format usable for GAP-3.4.2 in
the '/pub/incoming' directory of our ftp server 'ftp.math.rwth-aachen.de'.
The filename is 'trans15.zoo'. Just unzoo the file and follow the
instructions in the `read.me` file you get from the archive.
I'm currently working on lists for higher degrees (up to 30).
-- Lehrstuhl D fuer Mathematik, RWTH, Templergraben 64, 52056 Aachen, Germany,