See up to 36 live remote-desktop connections at once in a clean grid — a security-camera wall for your PCs, servers, and VPSes. Every viewport is live but view-only; click one to take full control.
Mainframe turns a pile of remote machines into a single wall you can watch at a glance. Add your PCs, servers, and VPSes and they appear as live RDP viewports in a grid you can size from 2×2 all the way to 6×6. The wall is view-only so nothing gets touched by accident; expand any tile for full control, go true-fullscreen, or yank a single screen out into its own free-floating desktop window and place it wherever you like.
A This-PC panel shows your own machine's address, name, and username so you always know exactly what to connect to, and a toast pops the moment any connection drops. Connections are saved with passwords encrypted by Windows DPAPI and reconnect on launch. It runs from the system tray and updates itself silently. Free to use — claim your license key and download it straight from this page.
- Live RDP wall, 2×2 up to 6×6, view-only by default
- Expand for full control, true-fullscreen, or pop out to a floating window
- This-PC panel + drop alerts so you're never guessing
- Saved connections (DPAPI-encrypted), tray, silent auto-updates
Mainframe is completely free. Downloads run through a free KVRNL account so every install gets its own license key.
- Go to kvrnl.io/products/mainframe/
- Create a free account — email verification, nothing else
- Claim your license key — instant, no waiting
- Download and install
Note
Mainframe isn't code-signed yet, so Windows SmartScreen may warn you on first run. Click More info → Run anyway. Code signing is on the roadmap.
- Free, one per product, issued from your KVRNL account.
- A key activates on one machine. The first device to activate it claims it.
- Switching computers? Hit Release device on your account page and the key is free to use again.
- Keys are checked over HTTPS at launch. See Privacy.
- Windows 10 or 11 (64-bit)
- A free KVRNL account for your license key
Mainframe sends KVRNL only what's needed to validate your license: the key, the product name, and a hardware ID. No telemetry, no analytics, no tracking, and none of your files. Full policy: kvrnl.io/privacy
v1.0.96 — 2026-08-14
- Fixed right-clicking a screen on the wall opening it instead of just showing its menu. Right-click now only ever opens the menu, and left-click is the one that opens a screen for control. Right-clicking the name bar or the hint next to it brings up the menu too, so the whole screen behaves the same way wherever you click it.
v1.0.95 — 2026-08-14
- The wall now tells you how to use it. Nothing ever said that a screen opens for control, so people watched the grid without realising they could go into a machine. Every screen's name bar now reads "Click to control", the whole bar is a single click instead of a double-click on the name, and clicking the picture itself opens that screen too. Hovering anywhere over a screen lights its bar up so it reads as a button rather than a photo.
- Settings has been rebuilt from the ground up. It's now organised around what you're trying to do instead of where things happened to sit: General for the wall and how the app behaves, Screens for your connections, Remote Desktop and Live Share for the two ways into this computer, and Help & info for the rest.
- The Screens page is new. Each connection is its own row showing whether it's connected, where it points and how many times it has reconnected — with Open, Reconnect, Edit and Remove right there on the row. The old page had one list and three buttons underneath that silently did nothing unless a row happened to be highlighted, and it rebuilt itself every two seconds, which threw away whatever you had just clicked.
- Removed the scrollbars nobody wanted. The connection list, the bug-report box and the settings pages themselves no longer carry their own scrollbars, and the stray horizontal bar along the bottom of every settings page is gone.
- "This PC" was doing three unrelated jobs at once, so it's now two clearer pages: Remote Desktop (your address, whether Windows is ready to accept visitors, and the microphone permission) and Live Share (your code, and who you've approved). Panels were renamed throughout to plain English, and every section now says what it's for.
- Removing a screen now asks first and tells you exactly what gets deleted, copy buttons confirm when they've copied, and Escape closes Settings.
v1.0.94 — 2026-08-14
- Fixed the microphone. Turning the mic on for a screen looked like it worked and then silently did nothing — speaker sound came through fine, but nothing you said ever reached the other end. Windows refuses a visiting microphone by default on every PC, so the machine you were connecting to was quietly throwing your voice away. Mainframe now switches that permission on for you on the PC you're connecting to, using the sign-in you already saved for it, before it reconnects.
- If Mainframe can't set that permission — usually because the saved sign-in isn't an administrator on that PC — it now says so instead of claiming the mic is live, and tells you exactly where to turn it on over there.
- Mainframe also checks Windows' own microphone privacy switches on your PC first. If the mic is switched off there, you get told which setting is blocking it rather than being left with a mic that connects and stays silent.
- The mic and speaker buttons now explain themselves. Both settings can only be applied while a screen is connecting, so switching one has always had to rebuild that screen — that brief flash was the setting being applied, not a fault. The message on screen now says it's reconnecting, and a second click while it's still working is ignored so you can't stack two rebuilds on top of each other.
- The Microphone section in Settings now spells out which direction it covers, because it only controls people who remote into your PC — not your own mic going out to a screen on the wall.
- Automatic bug reports now state plainly whether a mic can reach this PC and whether Windows is blocking the mic here, so a silent microphone is identified straight from the report.
v1.0.93 — 2026-08-08
- Fixed the fault that stopped Remote Desktop repairing itself on some PCs. Mainframe was working out the correct settings for the PC, applying them, bringing Remote Desktop up — and then throwing the working settings away and putting the broken ones back, every single time. It could never succeed on an affected machine no matter how many times anyone clicked Fix.
- The cause was Mainframe's own health check. It asked Windows for an encrypted connection, and on a PC set to use the standard Remote Desktop security level Windows answers "I don't offer that one" — a perfectly healthy reply from a working PC. Mainframe read that reply as a failure. It now recognises every valid answer Windows can give, so a PC that is working is never reported as broken.
- Mainframe will no longer undo a repair unless the PC was genuinely better off before. If the previous settings had no working Remote Desktop either, the newly worked-out settings are kept instead of being discarded, and a backup is left in place either way.
- Remote Desktop that is up and answering is now reported as working, instead of being failed over a bookkeeping mismatch in a support file.
- On Windows Home editions that have no built-in Remote Desktop Users group, Mainframe now says so plainly rather than reporting a confusing account error, and automatic bug reports now include the security level the PC offers and the result of a live Remote Desktop handshake.
v1.0.92 — 2026-08-07
- Fixed the update loop that could keep reinstalling and reopening the old version. Mainframe now targets the directory it is actually running from, waits for every app and watchdog process to close, and verifies the installed executable is the expected version before recording success.
- The updater now validates the downloaded installer before closing the app, records the installer exit result and installed version, and avoids launching duplicate copies after a silent update.
- Automatic bug reports now include the complete self-update state and installer logs, so a blocked update identifies the exact failure without asking anyone to collect files from the PC.
Full history → kvrnl.io/changelog/mainframe
Setup guides and how-tos → kvrnl.io/docs/mainframe
Important
We don't use GitHub Issues. Report bugs from inside the app — it's the fastest route to us and it attaches the details we need automatically.
- 🐛 Found a bug? Use Report a Problem inside Mainframe
- 💬 Chat with us → Discord
- ✉️ Anything else → kvrnl.io/contact
- ❓ FAQ → kvrnl.io/faq
Proprietary freeware — free to use, not open source.
This repository hosts the installer releases, documentation, and license for Mainframe. The application source code is not published. See LICENSE for the full terms.
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