*Termination and Complexity Competition 2025* http://www.termination-portal.org/wiki/Termination_Competition_2025 *Call for Participation* Since the beginning of the millennium, many research groups developed tools for fully automated termination and complexity analysis. After a tool demonstration at the 2003 Termination Workshop in Valencia, the community decided to start an annual termination competition to spur the development of tools and termination techniques. The termination and complexity competition focuses on automated termination and complexity analysis for all kinds of programming paradigms, including categories for term rewriting, imperative programming, logic programming, and functional programming. In all categories, we also welcome the participation of tools providing certifiable proofs. The goal of the termination and complexity competition is to demonstrate the power of the leading tools in each of these areas. The competition will be affiliated with the International Workshop on Termination (WST 2025, https://www.imn.htwk-leipzig.de/WST2025/). It will be run on the RWTH University HPC cluster <https://help.itc.rwth-aachen.de/service/rhr4fjjutttf/>. The final run and a presentation of the final results will be live at WST. We strongly encourage all developers of termination and complexity analysis tools to participate in the competition. We also welcome the submission of termination and complexity problems, especially problems that come from applications. A category is only run in the competition if there are at least 2 participants and at least 40 examples for this category in the underlying termination problem data base. If there is no category that is convenient for your tool, you can contact the organizers, since other categories can be considered as well if enough participants are guaranteed. For further information, we refer to the website of the termination and complexity competition: https://termination-portal.org/wiki/Termination_Competition_2025 <https://termination-portal.org/wiki/Termination_Competition_2025> _Important dates_ * Tool and Benchmark Submission: August 6, 2025 * First Run: August 20, 2025 * Bugfix Deadline: August 27, 2025 * Final Run: September 3/4, 2025 * Presentation of the results at WST: September 4, 2025