Hi! In Moose there is a project call "Hashtable". The goal of this project is to provide faster collections when they have a big number of elements. I think this is something that can be useful for more than just Moose so I extracted it to pharo-contributions so that we can use it and improve it more. https://github.com/pharo-contributions/Hashtable Have a nice day. -- Cyril Ferlicot https://ferlicot.fr