盡管還在孵化狀態中，CloudStack 4.0發布證明了自己的價值，這是CloudStack貢獻給Apache Software Foundation后發布的第一個版本。但這個版本并不代表CloudStack的成熟度或穩定性。在過去的6個月時間里，社區為今天的發布做了相當多的工作：增加新的功能，大量的Bug Fix，修復一些安全問題，完全的代碼審查(包括代碼自身及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