do some research on ruby 4

Based on my research, here's what I found about Ruby 4.0:

Ruby 4.0.0 Release Summary

Release Date: December 25, 2025 (official release)

Key New Features

1. Ruby Box 📦

• Purpose: Provides separation/isolation of definitions
• Status: Experimental feature
• How to enable: Set environment variable RUBY_BOX=1
• Class: Ruby::Box
• Functionality: Isolates/separates monkey patches, changes to global/class variables, etc.

2. ZJIT (Zero-Copy Just-In-Time)

• Status: Experimental (not production-ready)
• Purpose: Performance improvement through JIT compilation

Important Notes

⚠️ Production Readiness: According to recent analysis, while Ruby 4.0.0 was released, its best new features (Ruby Box and ZJIT) are not yet production-ready.

Additional Context

• Ruby 4.0.0 Preview 2 was released on November 24, 2025
• This release also coincided with Ruby's 30th anniversary (Ruby was created in 1995)

Where to Find More Info

• Official Ruby Announcement
• Preview 2 Announcement
• Production Readiness Analysis

Would you like me to dive deeper into any specific feature or aspect of Ruby 4.0?