2026 年最佳開源雲端平台

The open source cloud landscape covers a lot of ground. Some platforms give you a full IaaS stack with their own API surface. Others sit on top of existing hypervisors. A few implement the AWS API so your existing tooling carries over unchanged. The right choice depends on what you're replacing, what your team already knows, and whether you can afford to rebuild your operational model from scratch.

This is a practical comparison of the main options in 2026, written from our own vantage point as one of them. We've tried to be honest about where each tool fits and where it doesn't.

OpenStack

OpenStack is the oldest and most battle-tested open source cloud platform available. It covers compute (Nova), object storage (Swift), networking (Neutron), block storage (Cinder), identity (Keystone), and a dozen other services, each maintained as a separate project under the OpenStack Foundation. Telecoms, national research networks, and large enterprises run it in production at serious scale.

The operational complexity is real. Deploying OpenStack on anything other than a managed distribution requires substantial expertise, and keeping it running requires a dedicated team. If you are evaluating OpenStack for a team of five engineers, the maintenance overhead will consume more capacity than the platform returns.

OpenStack has its own API surface. Your AWS CLI, Terraform AWS provider, and eksctl workflows do not carry over. Teams switching from AWS need to learn a new operational model.

Best fit: Large organisations with dedicated infrastructure teams who need maximum flexibility and have no AWS tooling dependency.

Apache CloudStack

CloudStack is a mature IaaS platform originally developed by Cloud.com, open-sourced in 2010, and now under the Apache Foundation. It is simpler to deploy and operate than OpenStack and has been used by several commercial cloud providers as the underlying platform. The API is CloudStack's own, with some AWS EC2 API compatibility that covers basic instance management but not the full surface.

The community is smaller than OpenStack's and development pace has slowed, but the platform is stable and well-understood. For teams that need a proven IaaS layer without OpenStack's operational overhead, CloudStack is worth evaluating.

Best fit: Mid-size organisations building an internal cloud who want something more operationally accessible than OpenStack.

OpenNebula

OpenNebula is a European open source cloud platform with a strong following in HPC, research, and edge computing environments. It manages KVM, LXC, and Firecracker workloads and is designed to run on a lean footprint, making it viable on smaller hardware clusters where OpenStack would be overkill. It has its own API surface and a web interface that is considerably simpler to navigate than OpenStack's Horizon.

OpenNebula's community is smaller than either OpenStack or CloudStack, but the project is actively maintained and the documentation is good. For edge and research deployments where simplicity and low resource usage matter more than breadth of services, it is a credible choice.

Best fit: Research institutions, HPC environments, and edge deployments that need a lightweight IaaS layer.

Proxmox VE

Proxmox is a hypervisor management platform built on KVM and LXC, not a cloud platform in the IaaS sense. It gives you a web interface for managing virtual machines and containers across a cluster, along with Ceph integration for shared storage. It does not give you an API that applications call to provision infrastructure programmatically in the way that AWS, OpenStack, or CloudStack do.

Proxmox's star rose sharply after Broadcom's VMware acquisition triggered 800 to 1,500% price increases for standalone vSphere customers, and it is the most common destination for VMware refugees. The transition from vSphere to Proxmox is relatively straightforward for teams whose operational model is manual VM management through a web interface.

Teams who built their operational model on Terraform, eksctl, and the AWS CLI face a harder transition. Proxmox has no equivalent for those tools.

Best fit: Teams replacing VMware who manage VMs through a web interface rather than programmatically.

Ubicloud

Ubicloud (AGPL-3.0, Ruby, 12,300 GitHub stars) is a managed cloud service running on Hetzner and Leaseweb hardware that offers elastic compute, block storage, managed Postgres, Kubernetes, firewall, load balancer, and AI inference endpoints. Pricing runs 3 to 10x lower than equivalent AWS services, which is the primary pitch.

Ubicloud is a hosted service you access over the internet rather than software you deploy on hardware you own. For teams looking to cut their cloud bill without changing their operational model significantly, it is worth evaluating. For teams with data sovereignty requirements or air-gapped deployments, it is not the right answer because your data still lives on someone else's hardware.

Best fit: Teams on AWS who want to reduce their bill and can tolerate moving to a different hosted provider.

Spinifex

Spinifex (AGPL-3.0, Go, github.com/mulgadc/spinifex) is our product. It implements the AWS API surface — EC2, S3, IAM, EKS, ECS, ECR, VPC, EBS — on standard Linux bare metal, with no external control plane and no internet requirement.

The specific thing Spinifex does that none of the other platforms on this list do is preserve your AWS tooling investment. If your team has Terraform configs written against the AWS provider, eksctl workflows, IAM role structures, and scripts using the AWS CLI, those run against Spinifex with a single endpoint override, meaning far less rework to your operational model.

The performance case is documented in our OnLogic HX401 benchmark: CPU overhead runs 7% (sysbench single-thread: 1,358 events/s guest vs 1,456 bare metal). The docs also cover areas of active improvement.

Spinifex is the right answer for teams in air-gapped or sovereign environments, teams on edge hardware where AWS connectivity is unreliable, and teams with enough AWS tooling investment that rebuilding it on a new API surface is not a viable option. It is not the right answer for teams who need maximum breadth of services, or are primarily doing web-based VM management.

Best fit: Teams deploying to air-gapped facilities, edge hardware, or sovereign environments who have existing AWS tooling they want to preserve.

Choosing between them

The questions that narrow the field fastest:

Do you need AWS tooling compatibility? If your team has significant Terraform, eksctl, or AWS CLI investment, that eliminates OpenStack, CloudStack, OpenNebula, and Proxmox from the running. Ubicloud covers some AWS API surface but is a hosted service. Spinifex covers the core services required to run on hardware you own, with additional AWS service support added regularly.

Do you need to keep data on hardware under your direct control? That eliminates Ubicloud. The on-premise options are OpenStack, CloudStack, OpenNebula, Proxmox, and Spinifex.

Do you need to operate without internet connectivity? OpenStack can run air-gapped with sufficient effort, but it was not designed for it. Spinifex installs from a release tarball with no external dependencies and has no phone-home requirement.

Do you need to replace VMware with something familiar? Proxmox is the most direct path if your team manages VMs through a web interface. If your team provisions infrastructure programmatically, Proxmox does not cover what VMware gave you.

Given the many options for open source cloud providers, we encourage teams to research each option thoroughly to decide which option is best for them.

Full Spinifex documentation is at docs.mulgadc.com. For the other platforms: openstack.org, cloudstack.apache.org, opennebula.io, proxmox.com, ubicloud.com.

The quickest and easiest way to tell if Spinifex is the best option for you is through our hosted sandbox, which gives you 72 hours to try Spinifex without getting your own hardware involved. Sign up here: https://mulgadc.com/signup