Connect

Four in a Row - http://www.fierz.ch/4inarow.htm
A version of 'Connect Four' for Windows.

Fyrad - http://hem.passagen.se/peters/fyrad/
A 'Connect Four' variant for Windows with six built-in computer opponents and network play.

Get 5 - http://members.tripod.com/~Klaus_Tadsen/
Attempt to get five marbles in a row by placing them on the board. (DOS)

Gomoku - http://www.atomax.com/gomoku.stm
Play against the computer, laying out Xs and Os to put five in a row.

Nada - http://www.nada.connectfour.net/
A network variant of 'Connect Four' in Java.

Tick-Tack-Toe Master - http://styopkin.narod.ru/
A Go variant for Windows in which the object is to get five checkers in a row.

TicTacToe 3D Infinite - http://www.geocities.com/broudnoi/
Make five in a row on an infinite board, for Windows.