The H&K XM8 weapon system is effectively dead.
It lives on in the form of airsoft and video games.
H&K and the US Army developed the XM8 system as a replacement for the M16/M4 system.
Due to budgetary concerns the program was cancelled.
During testing the XM8 had two major concerns/faults.
Battery life for the intergrated electronic sight was very low and the handguards on the XM8 would melt under sustained fire.
Before those concerns could be fixed, the program was cancelled in 2005.
Even though it was canceled, H&K continued to tweak it.
They've renamed it the GVM-8, due to trademark/patent issues (US Army owns "XM8") and, in 2007, they demonstrated it to the Malaysian military & police (The Malaysians passed on it in favor of the FN F2000, which out performed the GVM8/XM8).
The XM8s still in US Army hands still get brought out and tested, as evident in the last extreme enviroment testing of the XM8 v SCAR-L v HK416 v M4.
Even though H&K still fiddles with it, it is on the back burner with the G11.
H&K is more concentrated on promoting/selling the HK416/417 system and G36 system.
(2007) Malaysian military/police testing H&K GVM-8 carbine.