
228 Chen Xu, Zhipeng Gui, Jing Li, Kai Liu, Qunying Huang, and Myra Bambacus
These companies include: British Telecom (BT),
1
China Telecom,
2
EVRY,
3
IDC Frontier,
4
KDDI,
5
Korea Telecom (KT),
6
Nippon
Telegraph and Telephone (NTT),
7
and Slovak Telecom.
8
Other com-
panies include Tata communications,
9
Nokia Research Center,
10
and
Logicworks.
11
• Maturity—CloudStack was rst released in 2010, and since then
it has been signicantly improved. It was rst released under the
GNU General Public License, Version 3 (GPLv3). When CloudStack
was donated to Apache Software Foundation (ASF) by Citrix in
April2012, the license was changed to the Apache L