> A tutorial, where the computer would play a game by itself,
> and would explain what it was doing and why;
if you are adventurous, you may try building on gnugo.el
(i.e., using emacs). as a tutorial platform, emacs has some
nice facilities built-in: interactive, text-oriented but also
supports images (which can be created/modified on-the-fly),
rich set of data types, subprocess management, network
connectivity (both client and server), and many many fellow
programmers (some of whom have been hacking for a long time).
this last point is to be underestimated at your own risk!
furthermore, gnugo.el can talk GTP, manage multiple games, go
into a gnugo-v-gnugo mode (see gnugo-extra.el for how), read
and write SGF files, browse gnugo.info directly, and "animate"
selected groups (of stones).
if, on the other hand, you are not adventurous, never mind...