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Mainframe skills are valuable.
Learning them was always hard.

Mainframe101 makes them learnable: a safe, guided mainframe in your browser, with Zed guiding every step. No installs, no VPNs, no setup.

app.mainframe101.org/dashboard

The Mainframe101 lab: the ZedBank job library in the dataset tree, a submitted job's spool output, and Zed explaining what each section of the spool contains.

app.mainframe101.org/dashboard

Runs entirely in the browser, on a laptop or an iPad. Nothing to install.

You're never stuck.

Zed explains what the system is doing and why it matters, then checks you actually understood it before you move on. You're never left staring at a blank green screen.

Nothing can break.

Everything is simulated. Experiment freely. There's no real system to bring down and no data at risk.

It actually sticks.

Active recall and quizzes are woven into the work, not bolted on at the end.

app.mainframe101.org/dashboard

The Mainframe101 lab: dataset tree, JCL editor, live jobs, and Zed guiding the lesson.

Scrollable, drag to see it all

app.mainframe101.org/dashboard

One system. Every skill.

One simulated z/OS environment: every subsystem you'll meet on a real one.

TSOJCLCOBOLDB2VSAMCICSRACFREXX

Open a URL. No setup.

No installs, no VPNs, no certificates, no Zowe. The barrier that stopped everyone is gone.

Pick up where you left off.

Progress saves as you go: every lesson, track and job you touch. Close the tab and resume exactly where you were.

Credentials you keep.

Earn OpenBadge 2.0 credentials and printable certificates you can show employers, plus milestone badges as you progress.

You're not doing exercises. You have a job.

You start as a new analyst at ZedBank, a fictional bank running on the mainframe. Real role-based tracks take you from your first command through JCL, COBOL, DB2, CICS, RACF and REXX. Zed explains the why before the how, every step.

Explore all features

The barrier

Learning it was never the hard part. Being left alone on one was.

You could get an account and an emulator and a connection, and hours later a real system would blink back at you, with no lesson, no hints, and no one to ask. That's the bit that beats people.

The old way

Mainframe101

Request an account. Wait.

Open a URL.

Install an emulator, configure a session.

Nothing to install.

VPN, certificates, Zowe CLI.

A browser tab. Laptop or iPad.

Read the manual and hope.

Ask Zed, in your own words.

One wrong command and you freeze.

Everything is simulated. Explore freely.

You don't get exercises. You get a job.

On your first morning you're a new analyst at ZedBank. Last night's statement job failed, and a member's account has to be right before the batch window closes.

app.mainframe101.org/dashboard

The first lesson of JCL Fundamentals, Welcome to the ZedBank batch floor: ZedBank's batch job library in the dataset tree, the starter HELLO job open in the editor, and Zed introducing the work.

Scrollable, drag to see it all

So you learn JCL because a job won't run.

Then COBOL, because the numbers are wrong. Then RACF, because someone can't get in. It's how everyone who is good at this actually learned it, in the order the work demanded.

app.mainframe101.org/dashboard

The HELLO job open in the Mainframe101 JCL editor, with the dataset tree and jobs list alongside it.

Scrollable, drag to see it all

Your job fails. That's the lesson.

You open the spool, read back what the system said, find the line that broke it, and submit again. That loop (fail, read, fix, run) is the actual job. Here it costs you nothing but the minute it takes.

app.mainframe101.org/dashboard

A failed compile job in the Mainframe101 lab: COMP1 marked FAILED in the jobs list, with its compiler output open in the spool, ending in one error.

Scrollable, drag to see it all

But you're not on your own.

Zed works through it beside you, explains what just happened before it shows you how, and checks you understood before you move on. Ask it anything, in your own words, at any point.

app.mainframe101.org/dashboard

Zed explaining what each section of a job's spool output contains, beside the learner's dataset tree and jobs list.

Scrollable, drag to see it all