In 2019, we announced that Crystal had multi-threading support. Since then, users wanting to squeeze a bit of those cores have the possibility to compile the app with the -Dpreview_mt flag and have access to parallel processing. However, five years later, the situation has not advanced much, with a working implementation that remains a preview feature.
This is a companion discussion topic for the original entry at https://crystal-lang.org/2024/02/09/84codes-manas-mt