Dear all, We would like to announce a week-long workshop on the PARI C library (the core of the computer algebra system PARI/GP), from 23rd to 27th June 2025, at the Institut de Mathématiques de Bordeaux. Website: https://pari.math.u-bordeaux.fr/Events/LIBPARI2025/ Organizers:   Bill Allombert          Aurel Page            The goal of the workshop is to gather people interested in the development of the PARI library, and to provide support to get started or to push current development projects. The prerequisites are knowledge of C programming and basic knowledge of GP (for instance having attended one PARI/GP Atelier) but no prior knowledge of the PARI library is required. The workshop will include: - libpari training: * in-depth introduction to libpari programming * description of the internal low-level datatype * libpari function naming convention, how to find the function one needs and how to avoid reimplementing existing functions. * how to implement new GP functions in C - short status reports on the current development projects - hacking sessions Do not hesitate to suggest topics for the training sessions. REGISTRATION: Please register as soon as possible by sending an email to one of the organizers; participation to the Atelier is free of charge. Five lunches and the conference dinner on Wednesday are offered but we cannot cover travel or other local costs. -- Bill and Aurel