The first one is a doom-like demo:
DEMO:http://flaswf.googlecode.com/files/z_ground_doom_style_room_test.swf
The second one is terrain generated by a heightmap and a texture map :
DEMO:http://flaswf.googlecode.com/files/z-ground_Terrain_new.swf
"I program, I dream." Bruce Jawn's flash blog
The first one is a doom-like demo: