European Summer of Code 2026
Funding stipends for contributors new to open source worldwide, and matching applied AI projects in Europe with international open source projects.
Projects
10+
Hubs
3+
Open Source Projects
17+
What is European Summer of Code?
European Summer of Code (ESoC) funds stipends for contributors new to open source, and matches open source projects and applied AI projects throughout Europe. We are much indebted to the Google Summer of Code for inspiration.
- Work with experienced mentors
- Build your portfolio
- Receive stipends for your work
- Join a community of like-minded developers
- Connect with applied projects and sponsors
- Increase visibility for your project
- Receive support for your ecosystem
- Expand your contributor base
- Connect with relevant open source projects
- Find talented developers
- Accelerate your development
- Contribute to the open source community
Batch 1 — 18 February 2026
Applications Open In
Program Details
Learn how European Summer of Code works for applicants, projects, and sponsors.
Projects
2026 projects are released in two batches: February 18 and March 19, with rolling releases thereafter. Projects have their own timelines and may come with their own terms of conditions.
Application Process
Applicants need to do two things to apply:
- 1
Register for ESoC
Complete the ESoC applicant registration form. - 2
Follow Project-Specific Steps
Follow any additional 'how to apply' steps from the project card of your preferred projects.
- 3
Meet Deadlines
Complete both steps before the project application deadline or batch deadline.
- 4
Wait for Results
You will receive a letter from ESoC on your application(s) no later than 6 weeks after the application deadline.
Recommendations
Ensure your submitted email address is correct, use the same name and email throughout the process, and submit early to avoid technical issues close to deadlines.
Onboarding Process
Private and public sector organizations wishing to host a project should submit a project sponsor form. Open source projects should directly contact our LinkedIn organization. Contact us on LinkedIn.
Funding Models
Choose between two funding models:
- 1
Option A: Donation for Stipend
You donate to a hub, and the hub contracts with the participant. The 'stipend' requires that a significant portion of the outputs are in the open domain.
- 2
Option B: Paid Internship
You can use your own contract template, in this case the hub will only act as matchmaker, and you will directly contract with applicants.
Project Card
Project cards should include: project title, logos, description, goals, organization info, technical details, application instructions, and deadlines.
Current Hubs
ESoC is organized in a decentral and distributed fashion, by hubs across Europe:
Hub Network
Current hubs include:
Expansion
We are actively looking to expand our network of hubs and affiliated open source projects. Get in touch on LinkedIn to discuss details.
Program Timeline
Key dates and milestones for the European Summer of Code 2026 program.
Information Event
ESoC info event sponsored by AI-on-Demand Platform. General info, applicant guide, Q&A.
EventAnnouncementBatch 1 — Applications Open
First batch of 2026 projects released. Applications open.
ProjectsApplicationsBatch 1 — Applications Close
Deadline for Batch 1 applications (18:00 UTC).
DeadlineApplicationsBatch 2 — Applications Open
Second batch of 2026 projects released. Applications open.
ProjectsApplicationsBatch 1 — Projects Start
Accepted Batch 1 applicants begin their projects.
ProjectsMentoringBatch 2 — Applications Close
Deadline for Batch 2 applications (18:00 UTC).
DeadlineApplicationsBatch 2 — Projects Start
Accepted Batch 2 applicants begin their projects.
ProjectsMentoring
2026 Project List
Projects will be announced on February 18, 2026.
Projects will be announced on February 18, 2026.
Stay tuned for exciting new projects!
2025 Project List
Explore projects from ESoC 2025.
Contribute to build the European AI-on-Demand Platform using OpenML - the open hubs for AI models, benchmarks, and projects. Funded by the Horizon Europe Programme of the EU.
Build the open source AI landscape for causal AI in time series, with applications across supply chain management and retail! In collaboration with, and sponsored by Electrolux.
Build open source AI for drug discovery, accelerating aptamer design for diagnostic and medical applications! Sponsored by German engineering services provider ecoSPECS.
Contribute to pgmpy, the Python library for causal learning! Help implementing cutting edge causal learning algorithms, improve interopability, and enhance the user experience.
Contribute to skore, the scikit-learn sidekick! Help improve data visualization in skore by implementing more displays, a Plotly display backend and providing access to underlying display data.
Contribute to pixi, the universal package manager! Help improve user experience, build user interfaces, and extend scope to more programming languages!
Contribute to rattler, fast mamba packager! Work on rattler-build to implement build process mechanisms, parallelize package installation, and improve the user experience.
Contribute to Gradient-Free-Optimizers & hyperactive! Help improve the Python toolboxes for optimization and data collection. Projects include implementing new optimizers, improving documentation, and more!
Build AI for design and equipment qualification of cleanrooms for biotech and pharmacological applications! Work with German engineering services provider ecoSPECS to fundamentally accelerate qualification processes in drug development, production, and monitoring worldwide.
Contribute to sktime! sktime offers a unified API for forecasting, classification, detection, and other learning tasks. Exciting projects are available in the areas of deep learning, foundation models, probabilistic forecasting, and more.
Deep learning for time series forecasting made easy with PyTorch. Projects are available, focusing on improving model interfaces, upgrading the package to include foundation models, and more!
Affiliated Open Source Projects
Meet some of the open source projects affiliated with the European Summer of Code 2026.
The European AI-on-Demand Platform — open hubs for AI models, benchmarks, and projects.
An optimization and data collection toolbox.
The open platform for sharing datasets, algorithms, and experiments.
Package Management Made Easy.
Causal learning in Python.
A multiverse of Prophet models for time series.
Python implementation of the Kalman Filter, Kalman Smoother, and EM algorithm.
Deep learning for time series forecasting made easy with PyTorch.
Deep learning for tabular data made easy with PyTorch.
Rust crates for fast handling of conda packages.
Base classes for scikit-learn compatible libraries.
Machine learning in Python.
Time series forecasting with machine learning models.
Scikit-learn compatible scoring and evaluation.
Probabilistic supervised learning in Python.
Preprocessing for heterogeneous tabular data.
The unified framework for machine learning with time series.
Become a Participating Organization
Join the European Summer of Code as a participating organization and help shape the future of open source and AI in Europe.