From Halopedia, the Halo wiki
The Requiem Forge was the name given to the nanotechnology assembler vats used for the construction of Promethean constructs, prior to Requiem's apparent destruction in early 2558. The forge presumably took the essences captured by the Composer and constructed the physical shells housing the sublimated mind. Given Requiem's destruction, it is unclear whether the Promethean forces of the Created are limited in number, or if alternate manufacturing sources have been found to replace the Requiem Forge.
List of appearances
- Halo: Official Spartan Field Manual (Indirect mention)