SNAKES (SNAKES is the Net Algebra Kit for Editors and Simulators) is a general purpose Petri nets library, primarily for the Python programming language but portable to other ones. It defines a very general variant of Python-coloured Petri nets that can be created and manipulated through the library, as well as executed to explore state spaces. Thanks to a variety of plugins, SNAKES can handle extensions of Petri nets, in particular algebras of Petri nets [4,26]. SNAKES ships with a compiler for the ABCD language that is precisely such an algebra. Finally, one can use the companion tool Neco [14] that compiles a Petri net into an optimised library allowing to compute efficiently its state space or perform LTL model-checking thanks to library SPOT [8,13]. This paper describes SNAKES’ structure and features.