From Spot 2.0 to Spot 2.10: What’s New? Alexandre Duret-Lutz 1(B) , Etienne Renault 1 , Maximilien Colange 2 , Florian Renkin 1 , Alexandre Gbaguidi Aisse 2 , Philipp Schlehuber-Caissier 1 , Thomas Medioni 2 , Antoine Martin 1 , J´erˆome Dubois 1 , Cl´ement Gillard 2 , and Henrich Lauko 2 1 LRDE, EPITA, Le Kremlin-Bicˆetre, France {adl,renault,frenkin,philipp, amartin,jdubois}@lrde.epita.fr 2 Bicˆetre, France Abstract. Spot is a C ++ 17 library for LTL and ω-automata manipula- tion, with command-line utilities, and Python bindings. This paper sum- marizes its evolution over the past six years, since the release of Spot 2.0, which was the first version to support ω-automata with arbitrary accep- tance conditions, and the last version presented at a conference. Since then, Spot has been extended with several features such as acceptance transformations, alternating automata, games, LTL synthesis, and more. We also shed some lights on the data-structure used to store automata. Artifact: https://zenodo.org/record/6521395. 1 Availability, Purpose, and Evolution Spot is a library for LTL and ω-automata manipulation, distributed under a GPLv3 license. Its source code is available from https://spot.lrde.epita.fr/. We provide packages for some Linux distributions like Debian and Fedora, but other packages can also be found for Conda-Forge [17] (for Linux & Darwin), Arch Linux, FreeBSD... Spot can be used via three interfaces: a C ++ 17 library, a set of command- line tools that give easy access to many features of the library, and Python bindings, that makes prototyping and interactive work very attractive. Our web site now contains many examples of how to perform some tasks using these three interfaces, and we have a public mailing list for questions. In our last tool paper [21], Spot 2.0 had just converted from being a library for working on Transition-based Generalized B¨ uchi Automata and had become a library supporting ω-automata with arbitrary Emerson-Lei [22, 41] acceptance conditions, as enabled by the development of the HOA format [5]. In the HOA format, transitions can carry multiple colors, and acceptance conditions are expressed as a positive Boolean formulas over atoms like Fin(i) or Inf (i) that tell if a color should be seen finitely or infinitely often for a run to be accepting. Table 1 gives some examples. M. Colange, A. Gbaguidi Aisse, T. Medioni, C. Gillard and H. Lauko—Previously at LRDE. c  The Author(s) 2022 S. Shoham and Y. Vizel (Eds.): CAV 2022, LNCS 13372, pp. 174–187, 2022. https://doi.org/10.1007/978-3-031-13188-2_9