The MULTI workshop series is the premier venue for researchers and practitioners working on multi-level modeling and multi-level software development. Multi-level modeling represents an extension of the object-oriented paradigm used in conceptual modeling, ontology engineering, and software development. In contrast to conventional two-level approaches, it supports an unbounded number of classification levels and introduces concepts and mechanisms that foster reuse, adaptability, and control. While multi-level languages and tools have reached considerable maturity, the field still offers numerous challenges.

Types of Submissions

MULTI 2026 invites five types of submissions:

• Regular research papers (10 pages)
• Position papers (5 pages)
• Challenge posters (only for the MULTI 2026 Vector Industry Challenge)
• Challenge papers (10 pages; for contributions to previous MULTI challenges)
• Industrial abstracts (2 pages)

Topics

Topics for regular and position papers include, but are not limited to:

• fundamental aspects of MLM, such as deep characterization and model composition
• integration of modeling and programming languages in a multi-level setting
• constraints in a multi-level setting
• definition of behavioral semantics in a multi-level setting, including simulation
• (industrial) case studies demonstrating multi-level techniques
• tool support for MLM
• MLM in education
• approaches for rearchitecting two-level models into multi-level models
• methods for discovering clabjects and their specializations and classification relationships
• design patterns addressing when and how to apply MLM
• model management in a multi-level setting

New Challenge: 2026 MULTI Vector Industry Challenge

In collaboration with Vektor Informatik GmbH, we provide a new challenge that should be addressed using a multi-level technology of choice.

A contribution to the MULTI Vector Industry challenge must be submitted as a poster. After the workshop, a joint journal publication of accepted solutions is planned. Further information and a detailed description of the challenge can be obtained here.

Submission Guidelines

Authors must submit their contribution as a PDF file via EasyChair.

Industrial abstract authors need to submit a maximum two-page PDF file containing the title of their contribution, the name and affiliation of authors, and an abstract of the multi-level problem they want to share in the workshop.

Submissions must adhere to the ACM formatting instructions. LaTeX users should use the provided LaTeX Template. Overleaf users should use the ACM Overleaf Template. Word users should use the interim ACM DOCX template. Challenge papers (see Challenges) must conform to the requirements specified in the respective challenge description.

Accepted papers will be included in the MODELS 2026 Companion Proceedings published by the ACM. Accepted industrial abstracts will be published on the MULTI 2026 workshop website.

Important Update for Publishing with ACM

Important update on ACMs new open access publishing model for 2026 ACM Conferences!

Starting January 1, 2026, ACM has fully transitioned to Open Access. All ACM publications, including those from ACM-sponsored conferences, will be 100% Open Access. Authors will have two primary options for publishing Open Access articles with ACM: the ACM Open institutional model or by paying Article Processing Charges (APCs). To find out whether an APC applies to your article, please consult the list of participating institutions in ACM Open.

Understanding that this change could present financial challenges, ACM has approved a temporary subsidy of 65% for 2026. The subsidy will offer:

• $250 APC for ACM/SIG members
• $350 for non-members

Note for this workshop: extended abstracts will be covered by a specific agreement with MODELS and will be published open-access free of charge.

Additional Notes for Paper Authors

Note that by submitting a paper to a MODELS workshop, authors acknowledge that they are aware of and agree to be bound by the ACM guidelines on plagiarism. In particular, papers submitted to MULTI 2026 must not have been published elsewhere and must not be under review or submitted for review elsewhere while under consideration for MULTI 2026.

Paper authors must ensure that all authors obtain an ORCID ID, so you can complete the publishing process for your accepted paper.