尽管还在孵化状态中，CloudStack 4.0发布证明了自己的价值，这是CloudStack贡献给Apache Software Foundation后发布的第一个版本。但这个版本并不代表CloudStack的成熟度或稳定性。在过去的6个月时间里，社区为今天的发布做了相当多的工作：增加新的功能，大量的Bug Fix，修复一些安全问题，完全的代码审查(包括代码自身及License兼容)等等。4.0版的更新如下：
Inter-VLAN Routing (VPC)
Site-to-Site VPN
Local Storage Support for Data Volumes
Virtual Resource Tagging
Secure Console Access on XenServer
Added the ability to create a VM without immediately starting it (via API)
Upload an Existing Volume to a Virtual Machine
Dedicated High-Availability Hosts
Support for Amazon Web Services API (formerly a separate package)
AWS API Extensions to include Tagging
Support for Nicira NVP (L2)
Ceph RBD Support for KVM
Support for Caringo as Secondary Storage
KVM Hypervisor support upgraded to work with Ubuntu 12.04 and RHEL 6.3
