To play Rummy, run the PLT Games program. (Under Unix, it’s called plt-games).
This is a simple variant of Rummy.
Put all cards in your hand into straights (3 or more cards in the same suit) and 3- or 4-of-a-kind sets to win. Each card counts for only one set. Aces can be used in both A-2-3 sequences and Q-K-A sequences.
When all of your cards fit into sets (the game detects this automatically), you win.
On each turn, you can either draw from the deck or from the top of the discard pile (drag from either to your hand), then you must discard one of your own cards (by dragging from your hand to the discard pile).
The status line at the bottom of the window provides instructions as you go. The computer player is fairly smart.