Apache CloudStack vs Microsoft System Center Virtual Machine Manager

Apache CloudStack is free, open-source software for deploying and managing networks of virtual machines as a highly available, scalable IaaS cloud platform. Organizations can use it to build public, private, or hybrid clouds. Its features include compute orchestration, network services, account management, resource accounting, a web interface, and an open API. Operators can manage clouds through a web UI, command-line tools, or REST API, with optional AWS EC2- and S3-compatible APIs. Supported hypervisors include XenServer or XCP, KVM, Hyper-V, and VMware ESXi with vSphere. Storage options include iSCSI, NFS, Ceph RBD with KVM, volume encryption, snapshots, and storage tiering. Authentication options include OAuth2 single sign-on, two-factor authentication, TOTP, SAML, and LDAP. The project says CloudStack can manage tens of thousands of physical servers across geographically distributed data centers. Long Term Support releases receive bug and security fixes for 18 months after the main release. Operators remain responsible for protections such as monitoring, host security, and defenses against DoS and brute-force attacks.

Microsoft System Center Virtual Machine Manager has no write-up on Specifiction yet; its figures are above.