# IBM z/OS

5 Hacker News commenters recommended IBM z/OS and 5 criticized it, November 2025 to November 2026. It was recommended in 4 of 13 months.

**Verdict:** Runs COBOL and mainframe workloads plus Python, Go and Rust; the main caveat is high cost, which rises with machine size.

## Why people recommend it

- Runs COBOL and modern languages (2 comments): "You can even run most cool Python, Go, Java, Rust, PHP among others, on systems like z/OS." ([source](https://news.ycombinator.com/item?id=49790392)) "z/OS still supports 50s COBOL frameworks and for good reason" ([source](https://news.ycombinator.com/item?id=50187336))

## What people warn about

- Very expensive overall (2 comments): "I think the biggest downside of IBM mainframes, is everything associated with them is super-expensive" ([source](https://news.ycombinator.com/item?id=48116153)) "that $10M represents the cost of only 10 months of operations on Z" ([source](https://news.ycombinator.com/item?id=46247575))
- Seen as archaic, legacy work (2 comments): "Miserable, pointless, banal, and archaic legacy as fuck mainframe work." ([source](https://news.ycombinator.com/item?id=47613127)) "I will not suggest building anything new on AIX or z/OS" ([source](https://news.ycombinator.com/item?id=49792489))

## Alternatives hackers recommend

- [Windows](https://hackerapproved.com/p/windows.md): 1287 recommend
- [macOS](https://hackerapproved.com/p/macos.md): 1041 recommend
- [Linux](https://hackerapproved.com/p/linux.md): 745 recommend
- [Haiku](https://hackerapproved.com/p/haiku-os.md): 115 recommend
- [NetBSD](https://hackerapproved.com/p/netbsd.md): 100 recommend

## Where to get it

- [Visit the official site](https://www.ibm.com/products/zos)

## Cite as

Hacker Approved, "IBM z/OS", https://hackerapproved.com/p/z-os/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).