Code3D has recently been open sourced. This allows people to edit the program code itself to modify and add to the features of the program.
Downloading the Source
The Code3D source is currently hosted on Launchpad and is kept track of as a Launchpad project. To view the project on launchpad visit http://www.launchpad.net/code3d.
Code 3D Wiki
For the most up to date information regarding the open source project please refer to the Code3D wiki at http://code3d.wikia.com.