As stated on, id Software is set to open new offices in Frankfurt, Germany:
As part of our continued global expansion, ZeniMax Media has opened (and is actively hiring for) a new technology development studio in Frankfurt – home to our German publishing operations. This team, an extension of id Software, will focus their efforts on idTech for DOOM and other titles under development at ZeniMax-owned studios.
You can also look at the ZeniMax job seeking page and see id Software Germany being listed.