Copyright (c) 2002 Tijn van der Zant, Marco Wiering 

This game is played on a 7x7 square board (other dimensions are possible):

GROUP - A set of orthogonally connected stones of the same color (like in Go).
TURN - At each turn, each player drops a friendly stone on an empty cell. 
A group with no adjacent empty cells is captured (there is no Ko rule).
A line with an odd number (>1) of stones of the same color can be captured in a custodian fashion, i.e., the line is captured when placed between two enemy stones (orthogonal or diagonal) or between an enemy stone and an edge.
GOAL - A player wins if he have a group adjacent to two opposite edges.
Some capture examples

These are some examples where the black stones would be captured if White played at [1].

An endgame

Black has already a winning position (even if it is White's turn). He just needs to drop at one of the [1] to create a group adjacent to two opposite edges.

The inspirational games where Go and Pente. Kanga is kind of Gonnect with custodian captures. Check the game's webpage.