Materialization is the process where virtual beings or data are transferred into the real world. This process can be programmed by using the Factory Interface, used by X.A.N.A., initiated by a Return to the Past, or triggered automatically by someone being devirtualized.
Though they likely share some code and resources, multiple materialization programs have been made. The shown implementations are listed below.
The Supercomputer provides a basic ability to materialize people with an intact Digital Genetic Code. This normally does not work on entities without a full code, such as Aelita or monsters. As shown in Exploration, the standard configuration of this ability only supported the surface sectors. In order for materialization to be performed from Sector Five, additional code was needed. As a result of these limitations, several extended versions have been made.
This version has been shown to have memory management problems as well, as shown in A Fine Mess, when data from Yumi and Odd got mixed up. Despite this, it is relatively fault tolerant, as shown in Nobody in Particular, when Ulrich's body and mind got separated, but it was still able to materialize Ulrich's mind, after some major delay.
This version was written by Franz Hopper. This version is automatically triggered when a compatible entity loses all their Life points or a Return to the Past is triggered. It can also be run manually.
It is service driven, like the real world's SSL and Apache Web Server. This was revealed in A Fine Mess, when the program bugged up, and needed to be restarted.
During Season 1, Jeremie and Aelita tried to materialize Aelita, and in Code: Earth, they finally succeeded in doing so. This was achieved in various stages with the Code: Earth Program. Note that this refers to not one program, but several different programs with various levels of success. The page explains these in more depth.
In False Start and A Bad Turn, X.A.N.A. used the scanners to materialize monsters into the real world. Kankrelats and Krabs are the only monsters that have ever been materialized in the real world. He managed to materialize a huge amount of Kankrelats and three Krabs as they destroyed the scanners after being materialized. X.A.N.A. later emulated this ability at the New Mexico Research Facility in Hard Luck to materialize Kankrelats as specters.
During Season 4, Jeremie tried to find a way to materialize William. He managed to do this in Down to Earth thanks to a data from a tower that X.A.N.A. used to materialize William to the Siberian Research Facility in Cold Sweat.
Most of the Replikas were based on copies of Lyoko. As a result, different instances of the same "vanilla" materialization processes were used. These versions are automatically triggered when a compatible entity loses all their Life points or a Return to the Past is launched. They can also be run manually. However The Skidbladnir acts as a catalyst in the process of materialization from the Replikas.
Since the Cortex was somewhat based on Lyoko with a different design, and a prototype; it didn't have a compatible materialization program built in. This was likely because Tyron lacked any Scanners, and was never shown ever virtualizing anything. This version is automatically triggered when a compatible entity loses all their Life points or a Return to the Past is performed. It can also be run manually.
As a result, in the episode Cortex, Aelita had to get to an interface, and get information on the system so people could be materialized from the Cortex; in order to prevent Yumi and Ulrich from being lost.
Without this version, whenever one of the Lyoko Warriors was devirtualized on the Cortex, a lot of the transmission would get lost on the way back, "but remained buffered on the Cortex," and normal materialization was impossible. With the addition of this program, the transmission would work correctly, resulting successful materialization. It was implied that the Skidbladnir was required to work as a relay for this version to work.
It's possible that this is not a separate virtualization program, but rather a set of networking scripts, so the scanners can receive and understand the Cortex's devirtualization data. This becomes more reasonable in Ultimate Mission, when the Cortex was shutting down, and as a result, the warriors required the Skid to materialize.
Dog Day Afternoon Version
Since Odd got digitally fused with Kiwi, in a virtualization accident of his own doing in Dog Day Afternoon, Jeremie had to separate them. As a result, Jeremie wrote a specialized materialization program to devirtualize a blended digital entity, and materialize its component entities.
A Fine Mess Version
At one point, the standard Materialization program bugged up, and dumped Yumi's mind into Odd's body, and vice versa. Aelita and Jeremie debugged the program, and fixed the damage by restarting the program.
This program isn't a materialization program by design, but does allow people to appear in the real world via a tower. It's more of a general purpose program than most materialization programs. Translation is a application of this.