Munich Replaces VMware, Oracle and Atlassian With Proxmox and Open Source

Speaking at Open Source Summit Europe in Prague, Munich’s Chief Digital Officer (CDO), Dr. Laura Dornheim, laid out how Germany’s third-largest city is aggressively replacing proprietary enterprise software with open-source alternatives while leaving the desktop operating system wars in the rearview mirror for now. As reported by ZDNET and corroborated by The Stack, Munich is pivoting away from heavyweights like VMware, Atlassian’s Jira and Confluence, and Oracle databases in favor of Proxmox, OpenProject, XWiki, and PostgreSQL.

For Windows administrators and IT architects watching licensing renewals climb across the industry, Munich’s latest pivot offers a masterclass in modern infrastructure pragmatism. Rather than fighting a bruising, high-visibility war over user interfaces and keyboard shortcuts on 15,000 municipal PCs, the city is quietly re-engineering the plumbing underneath—and projecting annual savings of roughly €1 million to €1.5 million or more in the process.

The Ghost of LiMux: Why Desktop Linux Lost to Politics, Not Bugs​

To understand why Munich’s current strategy is so deliberate, you have to revisit one of the most famous sagas in enterprise computing history. Back in May 2003, as Microsoft Windows NT 4.0 approached the end of its support lifecycle, Munich’s city council voted to ditch Windows in favor of a custom, Debian- and Kubuntu-based Linux distribution christened LiMux.

The rollout began in earnest in 2006, and by December 2013, the city had successfully migrated more than 14,800 desktop workstations to LiMux alongside open-source office productivity tools. According to a 2013 case study published by the European Commission’s Open Source Observatory, the project migrated roughly 15,000 seats, deployed the custom WollMux template and form management system, and saved millions of euros—a figure ZDNET notes was reported at roughly €11 million.

Yet the triumph was short-lived. Following municipal elections in 2014, the political winds shifted dramatically. By November 2017, the city council voted to reverse course and migrate its desktops back to Microsoft Windows with a target of 2020, while the grueling transition from LibreOffice back to Microsoft Office dragged on until 2023. Earlier reporting by ZDNET in 2020 estimated that the broader return to Microsoft and other proprietary vendors like Oracle and SAP carried an eye-watering price tag of €86.1 million.

Why scrap a working operating system environment? During her keynote in Prague, Dornheim addressed that exact question head-on. As quoted by ZDNET, she argued that open source in the public sector rarely fails for technical reasons; instead, it fails when it falls out of alignment with the prevailing political agenda. Dornheim noted that the reversal happened after a new municipal government struck an agreement that saw Microsoft relocate its German national headquarters to Munich.

That doesn't mean the LiMux era was friction-free. Even sympathetic observers and ZDNET’s reporting acknowledge that the original migration exposed just how painful it is to untangle a massive government workforce from Microsoft Office document formatting, complex macros, legacy workflows, and deeply ingrained user habits. When a clerk’s spreadsheet breaks or a cross-agency PDF form fails to render, the helpdesk—and eventually the mayor’s office—hears about it immediately.

Section Summary:

• Munich’s original LiMux project (2003–2013) successfully moved nearly 15,000 desktops off Windows NT 4.0 to Linux and LibreOffice.
• A post-2014 political shift—coinciding with Microsoft moving its German headquarters to Munich—triggered a costly, multi-year migration back to Windows and Microsoft Office that only wrapped up in 2023.
• CDO Laura Dornheim maintains that LiMux was undone by politics rather than technical failure, teaching the city that open-source initiatives require durable political and budgetary backing to survive.

Infrastructure First: Trading VMware, Atlassian, and Oracle for Open Source​

When Dornheim stepped into the CDO role in September 2022, she chose not to subject municipal workers to a third administration-wide desktop operating system whiplash. Instead, Munich focused its open-source ambitions where end users rarely look, but where enterprise software vendors extract massive recurring fees: the data center and collaboration tiers.

According to ZDNET’s coverage of Dornheim’s Prague keynote, Munich is actively executing or planning three marquee infrastructure migrations:

1. Virtualization: Replacing VMware with the open-source Proxmox Virtual Environment.
2. Project Management and Documentation: Migrating away from Atlassian’s Jira and Confluence toward OpenProject and XWiki.
3. Database Infrastructure: Adopting PostgreSQL as an open-source alternative to proprietary Oracle databases.

According to ZDNET, the virtualization and collaboration migrations alone are projected to save Munich approximately €1.5 million or more per year, while Dornheim noted the city is already realizing roughly €1 million in annual savings from its open-source shifts.

Inside Munich’s Official Hybrid Proxmox Strategy​

While conference keynotes often paint technology transitions in broad strokes, official municipal documentation from the City of Munich (stadt.muenchen.de) published on October 12, 2026, reveals just how calculated the VMware-to-Proxmox transition really is.

Following the acquisition of its incumbent virtualization vendor (widely understood across the IT sector as Broadcom’s acquisition of VMware) and the resulting upheaval in licensing models and pricing, Munich’s IT department (IT-Referat) and its internal service provider, it@M, spent roughly 18 months analyzing technical and economic alternatives. Rather than attempting a reckless "rip-and-replace" overnight, Munich adopted a deliberate hybrid virtualization architecture:

• Vendor-Certified Workloads Stay Put: Mission-critical systems that require strict vendor hardware/hypervisor certification—most notably SAP environments—will remain on the existing proprietary virtualization platform.
• Standard Workloads Move to Proxmox: A large majority of standard virtual servers will gradually migrate over several years to a newly built open-source platform powered by Proxmox.
• In-House Execution Without Bloated Headcount: Roughly ten existing specialists at it@M covering Linux, virtualization, storage, and automation are leading the multi-year rollout in parallel with existing operations, requiring zero additional job positions.
• Upstreaming Code to the Community: Rather than paying for locked-down custom connectors, Munich partnered with regional open-source specialist ATIX (based in nearby Garching) to invest roughly €20,000 into enhancing the open-source lifecycle management tool Foreman—contributing those features directly back to the upstream project for other enterprises and governments to use.

Similarly, the pairing of OpenProject and XWiki is no coincidence. In the European public sector, those two platforms have worked closely to build a unified counterweight to Atlassian’s cloud-first licensing push—including native XWiki integration introduced as an Enterprise add-on in OpenProject 17.6.0 in July 2026, allowing teams to link and generate wiki documentation directly from project work packages.

The Azure and GDPR Sovereignty Equation​

Where does Microsoft fit into Munich’s backend calculus today? While Windows and Office remain entrenched on the desktop, cloud adoption is a much stickier conversation. As reported by ZDNET, Dornheim pointed out that moving municipal workloads to Microsoft Azure without ironclad assurances of General Data Protection Regulation (GDPR) compliance would force the city to police and scrutinize exactly which employees are allowed to use each specific cloud tool.

That administrative and compliance overhead, she noted, weakens the business case for relying on Microsoft’s cloud ecosystem. Across Europe—from the German state of Schleswig-Holstein’s push to replace Windows and Microsoft 365 to Dutch tax authorities scrutinizing cloud lock-in —digital sovereignty is no longer an abstract philosophical talking point; it is a compliance and procurement headache that directly impacts IT governance.

Section Summary:

• Munich is targeting high-cost backend licenses—swapping VMware for Proxmox, Jira/Confluence for OpenProject/XWiki, and Oracle for PostgreSQL.
• Official City of Munich documentation confirms the Proxmox move is a pragmatic hybrid rollout: SAP and vendor-certified workloads stay on legacy hypervisors while standard VMs migrate gradually over several years.
• GDPR compliance hurdles and administrative overhead around Microsoft Azure continue to tip Munich’s risk-benefit analysis toward self-hosted or sovereign open-source tools.

Institutionalizing Open Source: OSPO, MUCGPT, and "Public Money, Public Code"​

Perhaps the biggest difference between 2006 and 2026 is how Munich organizes its IT governance. Under the banner of "Public Money, Public Code"—a coalition commitment dating back to 2020 that publicly funded software should be publicly shared —the city has built permanent institutional guardrails so its open-source momentum doesn't evaporate after the next election.

According to Munich’s official Open Source portal (opensource.muenchen.de), following a city council motion in February 2023, the city formally established a dedicated Open Source Program Office (OSPO) inside it@M at the beginning of 2024. Led by Kubernetes veteran Klaus Mueller alongside Chief Open Source Officer Dr. Dirk Gernhardt, the OSPO coordinates procurement advice, legal licensing reviews, community engagement, and upstream contributions. As The Stack reported from Prague, Dornheim explained that Munich now embeds a commitment into its procurement procedures making open-source software the default choice whenever economically, technologically, and strategically sensible.

Munich’s public software portal organizes this strategy around three pillars: Use, Improve, and Publish. And the city isn't just consuming code; it is actively shipping and funding it:

• MUCGPT (Municipal AI Toolkit): Mentioned by Dornheim in Prague as an internal LLM tool helping city staff draft and proofread emails, MUCGPT is published on Munich’s open-source portal under the permissive MIT license. Built with a React/TypeScript frontend, Python FastAPI services, Keycloak SSO integration, and PostgreSQL, MUCGPT acts as a secure, sovereign wrapper that connects to OpenAI-compatible LLM endpoints while keeping chat histories stored locally in the user's browser.
• DAVe (Traffic Data Analysis): In production since 2021, this custom municipal application commissions, records, and visualizes urban traffic counts. Because Munich released the code publicly, the city of Wolfsburg adopted DAVe for its own traffic planning—a model Dornheim hopes to turn from happy accidents into systematic inter-city sharing across Germany.
• The Open Source Sabbatical: To strengthen critical software dependencies, Munich created a funded sabbatical program open to both internal city developers and external programmers (who can receive temporary positions via digital@M targeting roughly 60% salary compensation). According to the city’s portal, its first sabbatical in early 2025 integrated an open-source multilingual AI chat service (using Llama 3.3 and Gemma 3) into the Integreat civic app for newcomers. Its second-half 2026 sabbatical funds security hardening, test suite expansion, and XML 1.0r5 support for libexpat, a foundational XML parsing library embedded in countless enterprise and Linux systems worldwide.

Section Summary:

• Munich’s Open Source Program Office (OSPO), launched in early 2024, institutionalizes open-source procurement and legal workflows inside the city’s IT arm.
• The city actively builds and shares reusable municipal code under permissive licenses (such as MIT and EUPL), including the DAVe traffic analyzer and the MUCGPT AI assistant platform.
• Through its Open Source Sabbatical program, Munich directly funds developers to patch and improve critical upstream dependencies like libexpat and civic apps.

What Windows and Enterprise Admins Can Learn from Munich's Playbook​

If you manage a predominantly Windows-based enterprise or municipal network, it is easy to dismiss European public-sector Linux stories as ideological exercises detached from commercial reality. But Munich’s 2026 strategy strips away the zealotry and leaves behind a remarkably shrewd playbook for any CIO or systems architect:

1. Don't Fight End-User Muscle Memory First: Forcing thousands of non-technical office workers off Windows and Microsoft Office overnight creates immediate political backlash. By keeping Windows on the desktop while swapping out hypervisors, databases, and project trackers behind the scenes, IT captures massive license savings without disrupting daily citizen services.
2. Embrace Hybrid Transitions Over Dogma: Munich’s refusal to force SAP off certified hypervisors proves that open-source adoption doesn't have to be an all-or-nothing purity test. Run Proxmox where it shines; keep proprietary support where compliance demands it.
3. Invest a Fraction of License Savings Upstream: Spending €20,000 to add needed enterprise features to Foreman—or funding a six-month developer sabbatical on a critical XML library—costs pennies compared to enterprise hypervisor and database renewal hikes, while permanently improving the tools your team relies on.

Munich learned the hard way that a flagship Linux desktop rollout can be undone with the stroke of a politician's pen. By moving the battleground to the server room, tying open-source adoption directly to municipal budget savings, and keeping certified enterprise workloads exactly where they belong, Munich may have finally cracked the code on sustainable public-sector IT.