Quest3D is a visual programming environment for realtime 3D. It's Windows only.
We made the 8 demos and The Endless Forest with it. We remade The Kiss in it (original was made with Blender). We developed Drama Princess in it. And we are making The Path with it.
http://tale-of-tales.com/TheEndlessForest
http://kiss.entropy8zuper.org/the/incorporator