Driving the Future of Mainframe Innovation | z/OS Modernization

Why 21CS
Products
- Our Products
  - SENTINELⁿ
    Comprehensive change management tool for z/OS
  - STRATUSⁿ
    Cloud object storage for z/OS | 21CS
  - Tape/Assist®
    Seamlessly migrates z/OS tape data
  - TRANSVERSEⁿ
    End-to-end, non-disruptive z/OS data migration
  - VECTORⁿ
    Modern, simplified dataset transfers
  - VSEⁿ
    Enhanced VSE experience compatible with previous versions
- What's Next
  - VERIFIⁿ
    Modern, adaptable JCL checker
  - OPTIMAⁿ
    The next generation of mainframe performance analytics
- Trusted IBM Partner
  - IBM Product Portfolio
- 21CS Partners
  - Global Partnerships
Introducing New UI for STRATUS

STRATUSn's new UI makes cloud object storage on z/OS simpler for everyone. Extend mainframe storage ...
Learn More
Solutions
- Our Solutions
Talk to a Mainframe Expert

Partner with experts who understand mainframe challenges and opportunities.
Learn More
Insights

Talk to An Expert

Introducing New UI for STRATUS
Why Object Storage?

z/OS Modernization
July 20, 2026
AI for QA with Python and ZOAU for the Seasoned Professional
I've recently started to use AI in my day-to-day work. Initially being a 'seasoned professional' - or just someone who has been working with mainframes for 45 years - I thought I'd skip the whole AI...

Mainframe Automation
July 15, 2026