We thank the ESRF Support groups for their valuable technical assistance in the development of ID21 and wish to acknowledge all the former members of the ID21 team who contributed to the successful building and development of the beamline:

• Lionel Andre (as Technician)
• Ray Barrett (as Beamline scientist)
• Bob Baker (as Technician)
• Olivier Dhez (as Post-doc)
• Diane Eichert (as Post-doc)
• Barbara Fayard (as Post-doc and then Visiting scientist)
• Burkhard Kaulich (as Post-doc)
• Wolfgang Ludwig (as Post-doc)
• Ulrich Neuhaeusler (as Post-doc)
• Sebastian Oestreich (as Thesis student)