Directory

Open Source startup ecosystem

We track 34 organisations in this sector across 6+ countries.

34 entries.

Aiven

Helsinki, Finland · Startup

Aiven is a Helsinki-based cloud data platform founded in 2016 that provides fully managed open-source data infrastructure services including PostgreSQL, Apache Kafka, Redis, Elasticsearch, and ClickHouse across all major cloud providers. The company raised over $270 million including a $210 million Series D in 2022 at a $3 billion valuation, making it Finland's most valuable startup at the time. Aiven serves thousands of customers globally and employs over 500 people. By abstracting the operational complexity of open-source data tools, Aiven enables engineering teams to focus on building rather than managing infrastructure.

Catch the Tornado

Wrocław, Poland · Venture Capital

Catch the Tornado is a Wrocław-based venture builder and investment firm founded by Divante alumni Piotr Karwatka and Tomasz Karwatka after Divante's exit. The firm builds and backs open-source, composable-commerce, and AI-first companies with hands-on operator support. Portfolio and venture-build references include Alokai (formerly Vue Storefront), Ramp Network, and Rigby.

Chris Aniszczyk

Sofia, Bulgaria · Person

Chief Technology Officer of the Cloud Native Computing Foundation (CNCF), the open-source foundation behind Kubernetes and the broader cloud-native ecosystem. He is an announced speaker at Kubernetes Community Days (KCD) Sofia 2026, addressing the regional cloud-native developer community.

Defguard

Warsaw, Poland · Startup

Defguard is a Warsaw-based open-source cybersecurity company building the only enterprise VPN platform that embeds multi-factor authentication natively at the WireGuard protocol level, closing the gap between network access and identity that standard WireGuard deployments leave open. The fully self-hosted platform unifies VPN connectivity, identity and access management, SSO (Google Workspace, Microsoft Entra ID, Okta, LDAP, Active Directory), firewall policy orchestration and SIEM integration in a single Rust-built stack that customers run entirely on their own infrastructure — with no third-party cloud dependency and no US CLOUD Act exposure, supporting GDPR, NIS2, HIPAA and ISO 27001 compliance. Defguard spun out of teonite, a Polish software venture builder co-founded by CEO Robert Olejnik, and was publicly released on GitHub in May 2023 under an AGPL licence; its open-source core has gathered around 2,700 GitHub stars, with enterprise features under a commercial licence. In May 2025 it raised €1.2M (PLN 5.2M) in a pre-seed round led by Polish VC Hard2beat, with SMOK Ventures, S20 Team and cybersecurity firm ISEC, plus angels including Łukasz Jesis (Xopero). Version 2.0, released in April 2026, re-architected the platform with high availability and built-in SSL termination.

DevConf.CZ 2026

Brno, Czech Republic · Event

Free, annual community conference organized by Red Hat Czech Republic, focusing on open source, Linux, cloud, and containerization. Attracts 1,800+ developers to Brno's Faculty of Information Technology. An essential event for open-source startups and developer hiring in the CEE region.

Hans Roth

Brussels, Belgium · Person

Hans Roth is Senior Vice President and General Manager for EMEA at Red Hat, the world's leading provider of enterprise open source software solutions and an IBM subsidiary. In this role he oversees Red Hat's business across Europe, the Middle East, and Africa, driving enterprise adoption of open source technologies including Red Hat Enterprise Linux, OpenShift Kubernetes platform, and Ansible automation. He is a senior technology industry executive with significant influence in the European enterprise software and cloud infrastructure market.

KCD Sofia (September 2026)

Sofia, Bulgaria · Event

Kubernetes Community Days (KCD) Sofia is a CNCF-affiliated, single-day, single-track cloud-native conference at the Sofia Event Center, capped at around 600 attendees. The programme features practitioner talks from teams running Kubernetes in production, covering platform engineering, observability, security, GitOps, FinOps and machine learning.

Mistral AI

Paris, France · Startup

Founded in April 2023 by former Google DeepMind and Meta AI researchers, Mistral AI has become one of Europe's most valuable AI startups. The company builds frontier large language models such as Mistral Large and Mixtral and follows an open-weight plus enterprise deployment strategy. Its products are used via API, cloud partners such as Microsoft Azure, and local deployments for regulated organizations requiring data control and model transparency. Le Chat is the company's conversational interface built on its model stack.

NumFOCUS

Austin, United States · Support Organization

NumFOCUS is a US-based 501(c)(3) nonprofit that promotes open source scientific computing through fiscal sponsorship of more than 60 projects, including NumPy, Pandas, and Jupyter. It operates the PyData educational program globally, which organizes conferences and community events for data scientists and developers around the world. NumFOCUS serves as a Super Organizer and institutional backbone for PyData PyCon Yerevan 2026.

Ondřej Mirtes

Copenhagen, Denmark · Person

Czech software engineer and creator of PHPStan, the popular static analysis tool for PHP that helps developers find bugs before runtime. He is a confirmed speaker at Laravel Live Denmark 2026 in Copenhagen, where he discusses static analysis and code quality in modern PHP.

Open Mercato

Wrocław, Poland · Startup

Open-source, AI-native commerce and operations framework co-founded in 2025 by Piotr Karwatka (creator of Vue Storefront / Alokai) and Tomasz Karwatka (founder of Divante). It provides modular infrastructure for building custom commerce, ERP and finance software with AI-assisted engineering, combining SaaS speed with bespoke flexibility.

Open Source Conference Luxembourg

Belval, Luxembourg · Event Organisator

Organiser of the Open Source Conference Luxembourg, a gathering of international Open Source Program Offices and related organisations. The conference exchanges experience on implementing and securing open-source software across the public sector, AI and large language models, cybersecurity, academia and humanitarian use.

Open Source Conference Luxembourg 2026 (October 2026)

Belval, Luxembourg · Event

A one-day conference at the Belval campus themed around leading by example in digital sovereignty, gathering international Open Source Program Offices and related organisations. Participants exchange experience on implementing and securing open-source software across the public sector, AI and large language models, cybersecurity, academia and humanitarian use.

Open Source Summit Europe 2026 (Oct 2026)

Prague, Czech Republic · Event

Open Source Summit Europe is the Linux Foundation's premier vendor-neutral conference for the global open-source ecosystem, featuring keynotes, breakout sessions, and a Solutions Showcase. The 2026 edition is hosted in Prague, convening maintainers, developers, technologists, and community leaders shaping the future of open source, with co-located events on the preceding days.

OpenSlava 2026

Bratislava, Slovakia · Event

The 14th edition of OpenSlava, Accenture's free conference on emerging technologies and open source held in Bratislava. The 2026 programme focuses on AI in the era of intelligent agents, with hands-on labs on day one and main-stage sessions on day two. The hybrid English-language event draws business and technology leaders, architects, software developers, students and educators from across Central Europe.

Piotr Karwatka

Wroclaw, Poland · Angel Investor

Co-founder of Divante and managing partner at Catch the Tornado, Piotr is among Poland’s most active operator-turned-angels. After scaling and selling Divante, he helped build a venture-builder model focused on open source, composable commerce, and AI-first startups. Portfolio references include Ramp Network, Vue Storefront, and Rigby, alongside investments linked to major outcomes such as Callstack.

PyData Yerevan

Yerevan, Armenia · Event Organisator

PyData Yerevan is the Yerevan chapter of the global PyData network, hosted at the American University of Armenia (AUA) Akian College of Science and Engineering. It organizes monthly meetups and is the primary organizing body for PyData PyCon Yerevan, an annual international Python and data science conference. The chapter fosters learning and collaboration among data scientists, machine learning practitioners, and Python developers across Armenia and the South Caucasus region.

Samuel Hassine

Paris, France · Person

Co-founder and CEO of Filigran, the open-source cyber-threat-intelligence company behind OpenCTI. A former French cyber-agency leader, he scaled Filigran with backing from Insight, Accel and Eurazeo.

Spring I/O

Barcelona, Spain · Event Organisator

Organizer of Spring I/O, a major European conference for the Java and Spring ecosystem. Spring I/O is an event organiser based in Barcelona, Spain. Organising events in the Events, Java, Developer Tools, Open Source space.

Taylor Otwell

Copenhagen, Denmark · Person

Creator of the Laravel PHP framework and founder of the company behind it, one of the most widely used open-source web frameworks. He is a confirmed speaker at Laravel Live Denmark 2026 in Copenhagen, where he addresses the Laravel ecosystem and modern PHP development.

The Linux Foundation

Prague, Czech Republic · Event Organisator

Nonprofit foundation supporting open-source projects worldwide and organiser of Open Source Summit Europe, its premier vendor-neutral open-source conference. The Europe edition convenes maintainers, developers, technologists, and community leaders, and in 2026 is hosted in Prague with co-located events.

Tomasz Karwatka

Wroclaw, Poland · Angel Investor

Co-founder of Divante and managing partner at Catch the Tornado, Tomasz invests in high-growth software companies shaped by strong product and engineering culture. His strategy centers on composable commerce, open-source infrastructure, and AI-powered products. Notable portfolio examples include Ramp Network, Vue Storefront, and Rigby, with broader exposure to high-value exits in the Polish tech ecosystem.

Wasp

Zagreb, Croatia · Startup

Wasp is an open-source, full-stack TypeScript web framework co-developed by Croatian founders Matija and Martin Šošić. It integrates React, Node.js, and Prisma through a declarative configuration language, generating complete web applications with built-in auth, background jobs, and deployment. The company is Y Combinator alumni (W21) and raised EUR 1.3 million in seed funding led by Lunar Ventures.

WordCamp Belgrade 2026

Belgrade, Serbia · Event

The official WordPress community conference for Belgrade, held over two days at Dom omladine Beograda. The 2026 edition expects more than 300 attendees across talks and hands-on workshops running in parallel halls, bringing together WordPress developers, designers, agencies and content creators.

WordCamp Europe 2026

Krakow, Poland · Event

Europe's largest WordPress community event, drawing thousands of developers, agency owners, founders and open-source contributors to the ICE Krakow Congress Centre. A Contributor Day on 4 June precedes two days of talks, workshops and networking. Strong ground for SaaS builders, plugin and agency startups, and bootstrapped founders in the open-source WordPress economy.