Since Broadcom reshaped VMware's subscription model, UK teams running steady, uncomplicated virtual estates are asking whether they still need vSphere at all. XCP-ng — the open-source Xen hypervisor from French vendor Vates, managed through Xen Orchestra — is the leanest credible answer. Use the calculator below to see how your host count and spend compare.
| VMs | Hosts | VMware VCF / yr | XCP-ng / yr | 3-yr saving |
|---|---|---|---|---|
| 50 | 3× | £50,304 | £1,800 | £145,512 |
| 100 | 4× | £67,072 | £2,400 | £194,016 |
| 250 | 8× | £134,144 | £4,800 | £388,032 |
| 500 | 15× | £251,520 | £9,000 | £727,560 |
All figures are indicative estimates for planning only and subject to change; licence prices vary by reseller and deal size, and any monthly finance figure is subject to credit approval — not a quotation.
Where XCP-ng beats VMware
The headline is licensing: XCP-ng is genuinely free and open-source, so you pay only for optional per-node Vates support if you want SLAs and phone cover. That turns a recurring vSphere subscription into a near-zero software line, which is why the savings on the calculator are so stark. There is no per-core metering, no bundle you did not ask for, and no vendor lock-in — the Xen codebase and Xen Orchestra are yours to run indefinitely, supported or not.
What you give up leaving vSphere
XCP-ng covers the fundamentals well — live migration, HA restart on host failure, snapshots and Xen Orchestra backup — but its ecosystem is narrower than VMware's. There is no mature equivalent to DRS automatic load-balancing, so workload placement stays more manual. Third-party tooling, monitoring integrations and installed-base knowledge are thinner than vSphere, and thinner than Proxmox too. For predictable, well-understood workloads that rarely tips the decision; for sprawling, dynamic estates it can.
Migrating from VMware to XCP-ng
Vates has invested heavily in the exit path. Xen Orchestra now ships a built-in V2V tool that streams ESXi VMs across agentlessly, with warm migration across ESXi versions including VMFS6 and vSAN, so cut-over downtime is minimal. Veeam's own XCP-ng support has landed for 2026, closing the backup gap that once held teams back. We scope the pool design, storage and network mapping, and a phased UK migration so nothing production-critical moves before it is proven.
FAQs
Is XCP-ng really free, or are there hidden VMware-style costs?
The hypervisor and Xen Orchestra are open-source with no licensing fee — that part is genuinely free forever. The only optional cost is a Vates support subscription, priced per node, if you want SLAs, phone support and managed backups. There is no per-core metering or mandatory bundle, so your software spend can legitimately fall to nearly nothing versus vSphere.
How does XCP-ng compare with Proxmox as a VMware alternative?
Both are free, open-source and capable of the core essentials. XCP-ng, built on Xen and backed by Vates, is arguably the leaner, more focused option and pairs neatly with Xen Orchestra. Proxmox has a broader ecosystem, integrated backup server and larger community. For simple, stable workloads XCP-ng is often the tidier fit; busier estates may prefer Proxmox's breadth.
Can I migrate my existing VMware VMs to XCP-ng without major downtime?
Yes. Xen Orchestra includes an agentless V2V tool that streams ESXi virtual machines directly into XCP-ng with warm migration, supporting VMFS6 and vSAN across ESXi versions, so cut-over downtime is short. We plan the pool, storage and networking first, then move workloads in phases so each is validated in XCP-ng before the old vSphere host is retired.