Windows games on a Mac —
no floaty aim, no stutter.

A bottle

Its own folder with its own C: drive, registry and settings. The store and your games install into it rather than into your system, and they go away entirely when the bottle does. It is not a sandbox: the Z: drive inside points at the root of your Mac — that is how the compatibility layer itself works — so a game reaches files exactly as far as macOS lets Uncork reach them. You can keep several bottles, one for a heavy game, for instance.

The store inside it

Uncork installs the Windows build of Steam and fixes what usually breaks in it on a Mac. The Epic Games Launcher is supported too — the library shows games from both stores together. You sign in inside the store itself, install what you bought, and see it in the Uncork library.

You play

Play starts the game with D3DMetal or DXMT. Uncork watches the processes, keeps a log, and stops the screen from dimming while you are in a match.

The mouse is read directly

macOS delivers mouse events in bursts, once per display frame. Fine for a desktop; in a shooter your aim stutters, because about eight movements arrive as one lump. Our driver reads the device's own HID reports at the device's own rate. In CS2 you feel it immediately — this is the thing the whole project started for.

needs the Input Monitoring permission; without it the driver behaves like the stock one

Frames reach the screen evenly

An average fps says nothing about smoothness: CS2 at 118 fps shows gaps between frames on screen that jump from 4 to 13 ms, and the picture jerks. Even frames starts every frame on an even grid matched to the display's steps — 120, 80, 60 — and releases each finished frame at the same point, so it reaches the screen at equal intervals. Auto watches how frames actually hit the screen and holds them only when that makes them more even.

CS2 at 80: 87% of intervals within 1 ms of the mean, versus 18% without it; latency to the screen did not grow — 19 ms versus 21

A held key no longer shakes the picture

CS2 takes macOS key auto-repeat badly: stand still, hold a key, and the image trembles. Uncork switches repeat off while the cursor is hidden — that is, in the game — and switches it back on when the cursor returns, so chat and console type normally.

Two DirectX renderers

Apple’s D3DMetal lets the CPU run ahead of the GPU, and that turns into mouse lag. DXMT keeps the frame queue short, and the aim feels steadier on it. What that costs in frames we honestly do not know: we never ran a matched comparison on one scene, and an impression from ordinary play is not a measurement. Which matters more is your call: one click in the bottle settings, separately for each bottle.

We measure instead of promising

The driver can log how many frames are actually queued up and how many milliseconds a mouse movement waits to be handled. So "it got better" here is a number, not a feeling — and when an idea did not work, the numbers said so and we dropped it.

DualSense instead of a mouse — from the sofa

Connect a DualSense, DualShock 4 or Xbox controller and a badge with its battery level pops up in the corner of the window. The touchpad moves the pointer like a laptop trackpad, two fingers scroll, ✕ clicks, ○ is Esc, the d-pad sends arrow keys, L1 and R1 switch tabs. Pick a game and launch it without getting up. While a game runs, the mode stays quiet: the controller belongs to the game.

needs the Accessibility permission; over Bluetooth the DualSense touchpad reports the finger every ~15 ms — Uncork smooths the steps to the display refresh

Game Mode turns on for Windows games too

macOS gives a game CPU and GPU priority and polls wireless controllers and headphones twice as often — but only if it recognises the process as a game. A Windows game is just an anonymous program to it. Uncork launches every game from its own tiny app in the Games category, and macOS then turns Game Mode on by itself when the game is full screen and in front. No Xcode, no Terminal switches.

switchable in the bottle settings; while Game Mode is on, macOS itself shows its icon in the menu bar

An Apple Silicon Mac.

M1 and newer. Uncork does not run on Intel Macs.

macOS 14 or newer.

We test on the current one; older versions are untested.

Nothing to install by hand.

Uncork downloads the graphics libraries itself — about 250 MB, once, with a checksum check. No Terminal needed.

Disk space.

The runtime and Steam come to about 3 GB: 1.1 for the engine and 1.7 for a bottle with Steam in it, measured here. After that it is whatever the games weigh. CS2 needs 85 GB, and better with room to spare: its updates ask for more on top. The app shows you the free space before anything is installed.

Rosetta 2.

Tools inside the bottle ask for it, and until it is there the app will not let you create a bottle — the checks screen says so. The same screen has a button that installs it: Apple's own command, no terminal. On Macs that have run anything Intel-built, it is usually already there.

Your own Steam account.

You buy the games yourself. Uncork downloads nothing outside Steam.

About performance, honestly

A compatibility layer costs frames. Uncork will not turn a laptop into a gaming PC, and we will not draw charts where it performs "like native".

What we do instead: remove the things that ruin how a game feels — a stuttering aim, mouse lag, a trembling picture. Sometimes that matters more than ten frames.