The CAOS problem-solving environment: recent developments Marcel Carbillet a , Gabriele Desider`a b , Evelyne Augier a , Andrea La Camera b , Armando Riccardi c , Anthony Boccaletti d , Laurent Jolissaint e , Diyana Ab Kabir a a UMR 6525 H. Fizeau, Universit´ e de Nice Sophia Antipolis/CNRS/Observatoire de la Cˆote d’Azur, Parc Valrose, 06108 Nice Cedex 2, France; b Dipartimento di Informatica e Scienza dell’Informazione, Universit`a di Genova, Via Dodecaneso 35, 16146 Genova, Italy; c Istituto Nazionale di AstroFisica - Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy; d UMR 8109 LESIA, Observatoire de Meudon/CNRS, 5 Place Jules Jansen, 92195 Meudon, France; e aquilAOptics, Rue de la Chˆatellenie 4, 1635 La Tour-de-Trˆ eme, Switzerland ABSTRACT We present recent developments of the CAOS problem-solving environment (PSE), an IDL-based software tool whose original aim was to define and simulate as realistically as possible the behavior of a generic adaptive optics (AO) system —from the atmospheric propagation of light, to the sensing of the wave-front aberrations and the correction through a deformable mirror— but which results in a widely more general tool now. In fact, the different developments made through the last years result in a very versatile numerical tool com- plete of a global graphical interface (the CAOS Application Builder), a general utilities library (the CAOS Library), and different packages dedicated to a wide range of astronomical-optics-related scientific topics: the original package designed for end-to-end AO system simulations (the Software Package CAOS), an image sim- ulation/reconstruction package with interferometric capabilities (the Software Package AIRY), an extension of the latter specialized for the LBT instrument LINC-NIRVANA (the Software Package AIRY-LN), an ad hoc package dedicated to the VLT instrument SPHERE (the Software Package SPHERE), and an embedment of the analytical AO simulation code PAOLA (the Software Package PAOLAC). We present the status of the whole CAOS PSE, together with the most recent developments, and plans for the future of the overall tool. Keywords: Adaptive optics, numerical simulation, image reconstruction, CAOS problem-solving environment, CAOS Application Builder, CAOS Library, Software Package CAOS, Software Package AIRY, Software Package SPHERE, Software Package AIRY-LN, Software Package MAOS, Software Package PAOLAC. 1. INTRODUCTION The name CAOS (which stands for “Code for Adaptive Optics Systems”) was originally used to describe the Software Package CAOS which permits end-to-end numerical modeling of adaptive optics (AO) systems. Since a few years, it also describes the CAOS problem-solving environment (PSE, also called sometimes “system”), which allows to clearly separate in its own bosom the scientific part of the original Software Package CAOS from the global interface and global structure of the tool, permitting also to complete the whole suite with a number of other Software Packages covering a wider area of astronomical-optics-related scientifical topics, such as Further author information: (Send correspondence to M.C.) E-mails: M.C.: marcel.carbillet@unice.fr, G.D.: desidera@disi.unige.it, E.A.: evelyne.augier@unice.fr, A.L.C.: lacamera@disi.unige.it, A.R.: riccardi@astro.arcetri.it,, A.B.: anthony.boccaletti@obspm.fr, L.J.: laurent.jolissaint@aquilaoptics.com, D.A.K.: diyana126@yahoo.com.