4.1 open Due in about 5 months (12/25/2026) 68% 19 issues (13 closed — 6 open) Related issues Feature #8948: Frozen regex Actions Feature #21768: Remove deprecated functions Actions Feature #21788: Promote Thread::Monitor to a core class Actions Feature #21821: Add Stack and SizedStack classes Actions Feature #21881: Split the root box into the (newer) root box and the master of copied user boxes Actions Feature #21998: Add {Method,UnboundMethod,Proc}#source_range Actions Feature #22010: Update to Unicode 18.0 Actions Feature #22081: Core type definition migration from `ruby/rbs` to `ruby/ruby` Actions Feature #22226: Ractor: class/module ownership -- restrict modification to the Ractor that created it Actions