The earliest IGS was the [color=red]Geometric Supposer[/color], which was developed in the early 1980s.[br][br][list][*] Schwartz; Yerushalmy and Wilson (1993). The Geometric Supposer: What is it a Case of?. Hillsdale, NJ: Lawrence Erlbaum Associates.[/list]

[list][*][color=red][url=http://www.cabri.com/]Cabri[/url] (Jean-Marie Laborde, 1986-)[/color][*][color=purple][url=http://www.cinderella.de/]Cinderella[/url] (Jürgen Richter-Gebert and Ulrich Kortenkamp, 1998-)[/color][/list]

[list][*][color=red][url=http://www.dynamicgeometry.com/]Geometer's Sketchpad[/url] (Nicholas Jackiw, 1986-)[/color][*][color=blue][url=http://www.mit.edu/~ibaran/kseg.html]KSEG[/url] (Ilya Baran, 1996-2007)[/color][/list]

[list][br][*] [color=purple][url=http://yiijima.sakura.ne.jp/wiki/e01/]GC[/url] (Yasuyuki Iijima, 1989)[/color][br][/list]