MPS Community
Meetup 2026

In this talk, we will share the current status of Kocelot, a project developed at JetBrains. Kocelot aims to make it possible to embed DSLs directly into domain-specific applications. We believe that not only should the language be tailored to its domain experts, but so should the application in which it is presented. This is difficult to achieve with traditional language workbenches.

Our goal is therefore to provide an SDK that enables developers to define a language and integrate it into their application stack with minimal effort. In the current milestone, we are delivering an SDK that supports applications built with Spring Boot, PostgreSQL, and Kotlin on the backend and React on the frontend. The architecture is designed with further integrations in mind.

About the speaker

Radimir works at JetBrains as the technical lead of Kocelot. He previously worked on JetBrains MPS and on bringing a DSL for biological knowledge to the web.

Automation in an MPS project often begins with a build script copy-pasted from another project, with minimal adaptations. It compiles the project and runs some tests, but maintainers may struggle to understand the build and extend it.

This talk presents a practical path from such an inherited build to maintainable project automation. Using examples from real MPS projects, we will establish a structured Gradle build and progressively add model checking, architecture enforcement, consistency and pending migration checks. We will also examine how MPS projects can make use of headless access to MPS models and how the checks can help maintain a project across several MPS versions simultaneously.

You will learn how to

• Set up a maintainable, deterministic Gradle build for your project.
• Run model checks in local and CI workflows.
• Enforce project conventions and architectural boundaries.
• Maintain a library across multiple MPS versions.

About the speaker

Sergej has been working with JetBrains MPS since 2015, specializing in the infrastructure of MPS projects. Over the years he has helped customers across a range of industries, including automotive, medical, and tax/payroll, with MPS performance, architecture, and migrations. He writes about MPS at specificlanguages.com and hosts free office hours for MPS developers at every level, from students to professionals.

In a sense, MDSE turns ordinary users into software developers. Inevitably, as the adoption of an MDSE solution grows, it encounters many of the same challenges as traditional software development, such as organizing a code base into multiple modules, some of which are more general in nature. Since our users are non-technical, conventional software engineering solutions cannot be applied directly.

This presentation demonstrates a solution that enables non-technical end users to reuse their MPS projects without requiring them to specify build details. The solution extends the MPS build language with declarative constructs for specifying dependencies and the artifacts that are required or produced. By making a few assumptions, for example that each repository contains a single project, it becomes possible to generate build scripts for end-user specifications, including dependencies on specifications located in other projects, without requiring users to provide technical implementation details. The source code will be made available before the start of the conference.

Demo outline: project dependencies for end users

• MPS project A using a sample language
• MPS project B extending project A (with references to concepts in project A)
• IDE action to make A available in MPS when only B is opened
• Continuous Integration for B (and A)

About the speaker

Various software engineering jobs, among which experience in model driven software engineering using Xtext. PhD in history of logic and philosophy of mathematics. Senior model driven software engineer and product owner ALEF at Belastingdienst.

A manufacturer of industrial lasers needs to program its machines for diverse activities across a range of domains. Over time, several editors were developed for these activities, as the company nowadays provides not only devices, but integrated solutions. Due to the different focus areas, these editors use different representations of the underlying program, which complicates data exchange and close cooperation.

As a solution, we developed a DSL capable of representing relevant aspects of a program in a unified language. We used MPS for prototyping, C# for backend development, and TypeScript for frontend implementation. LionWeb ties all technologies together.

This talk presents the customer's challenges, the advantages and issues with DSL-based development, and how LionWeb underpins the solution. We present the language development process, and how LionWeb ideas helped in a real-world project: unified M2/M1 representation, generators and tools for C# and TypeScript, the bulk and delta protocol, language evolution, and derived models.

About the speaker

Niko heads the Model Driven Engineering team at F1RE and supports colleagues and customers with language engineering and DSL expertise.

AI systems are being connected to almost every modern coding platform. For general-purpose languages like C or Scala, this is a one-shot operation: every user will use the same language and functionality. In contrast, domain-specific languages, especially in JetBrains MPS, face the challenge of being highly user-specific, which makes useful and scalable AI integration a major challenge.

In this talk, we present F1RE's agent-support DSL, Genie. Genie is a toolbox for defining and implementing agent-specific functionality in MPS. We implement the toolbox as an aspect, making AI support a first-class citizen of domain-specific language development.

About the speaker

Atanas is a Model Driven Engineer at F1RE, where he has worked since December 2021.