Lines 3D is a program for viewing a simple 3D text file format (*.rot) in windows. There are many of these files on the internet but before Lines 3D was made they could only be viewed on macs or in dos. 3D objects are built from lines and circles, which makes it very simple to create and edit 3D objects easily simply by typing coordinates into a text file. When opened in the program, the 3D model can be rotated, zoomed and moved around to any view position using the mouse and several options allow the user to specify exactly how the model should be displayed. There are more advanced 3D software out there but the small size of the program and the simplicity of use make it very useful for people who need to share 3D files since the program can simply be sent with the text files. No installation is needed and no external programs or APIТ‘s (such as OpenGL or DirectX) are required.