4.0 open about 6 months late (12/25/2025) 95% 20 issues (19 closed — 1 open) Related issues Feature #19057: Hide implementation of `rb_io_t`. Actions Feature #21221: Proposal to upstream ZJIT Actions Feature #21262: Proposal: `Ractor::Port` Actions Feature #21268: Implement a lock-free hash set for fstring table Actions Feature #21275: Update to Unicode 17.0 Actions Feature #21311: Namespace on read (revised) Actions Feature #21550: Ractor.shareable_proc/shareable_lambda to make sharable Proc object Actions Feature #21557: Ractor.shareable_proc to make sharable Proc objects, safely and flexibly Actions Feature #21701: Enumerator.produce accepts an optional `size` keyword argument Actions
4.1 open Due in about 6 months (12/25/2026) 69% 13 issues (9 closed — 4 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 #22010: Update to Unicode 18.0 Actions Feature #22081: Core type definition migration from `ruby/rbs` to `ruby/ruby` Actions