Magnetized points
From JSXGraph Wiki
The underlying JavaScript code
var brd = JXG.JSXGraph.initBoard('box', {axis:false, boundingbox: [-5, 5, 5, -5]}),
li = brd.create('line', [1,2,3]),
ci = brd.create('circle', [[2,2],1]),
p0 = brd.create('point', [-2,0], {color:'blue'}),
p = brd.create('point', [-2,-2], {attractors: [li,ci,p0], attractorDistance:0.2, snatchDistance: 2});