The original way of passing data to the program, before the web front end was added, was with a board file, which looked a lot like the board files which John Chew's DOoMs generate. In expert mode, you can enter one of these files directly and bypass the possibly slower form filling. Here are the three main ways you can run simulations:
Here is some sample output from the command-line version:
pizzabox:~/scrabble/jacsim> ./simul -ldd s bdsim2
After 0 iterations:
 27.0 ( 0.0)  6f LOB
 26.5 ( 0.0)  4i BUHL
 26.0 ( 0.0) l2  BOA
 24.0 ( 0.0)  4k HULLO
After 400 iterations:
 27.8 (43.5)  4i BUHL
 23.6 (47.7)  6f LOB
 17.4 (53.2)  4k HULLO
 12.4 (39.8) l2  BOA
After 800 iterations:
 26.9 (44.4)  4i BUHL
 22.7 (45.7)  6f LOB
 18.8 (53.5)  4k HULLO
 12.0 (41.0) l2  BOA
...
After 38800 iterations:
 27.2 (45.7)  4i BUHL
 22.8 (44.9)  6f LOB
 21.3 (51.9)  4k HULLO
 11.8 (42.2) l2  BOA
After 39200 iterations:
 27.2 (45.7)  4i BUHL
 22.8 (44.8)  6f LOB
 21.3 (51.9)  4k HULLO
 11.8 (42.2) l2  BOA
After 39600 iterations:
 27.1 (45.7)  4i BUHL
 22.8 (44.8)  6f LOB
 21.3 (52.0)  4k HULLO
 11.8 (42.2) l2  BOA
After 40000 iterations:
 27.1 (45.7)  4i BUHL
 22.8 (44.8)  6f LOB
 21.3 (52.0)  4k HULLO
 11.8 (42.2) l2  BOA