Rebound: replacing Windows 11 system apps with WinUI rewrites

What the project is and how it describes itself

Rebound is a Windows modernization project focused on improving the user experience and updating system functionality. It replaces legacy or unmaintained Windows applications with modern implementations built using current technologies, and it aligns with the Windows 11 design direction by extending WinUI to areas of the system that still rely on older frameworks.

The stated goal is a cleaner and more consistent application experience, and the vision is worded broadly: a consistent OS with no leftovers and many cross application features. The README says both consumers and power users deserve the Windows 11 they love, and that the project aims to provide as much customizability and consistency as possible while keeping it lightweight and easy to use. The tagline in the header is shorter: Modern Windows done right, rewritten.

The repository description calls it a WinUI rewrite project of Windows 11 system apps, and the homepage is ivirius.com, with a documentation site at ivirius.com/docs/rebound.

Two warnings sit at the top of the README and set expectations more accurately than the tagline does. The document covers the upcoming Rebound v0.1.0, so some features displayed may not be available for consumers yet. And the project is still in its early stages of development, v0.0.10 has known issues that will be fixed once v0.1.0 is released, and the document is incomplete, with links to the official website possibly pointing nowhere valid.

Those two warnings are worth reading before anything else, because they are the difference between a tasteful system app replacement and a system modification that leaves a machine in a state nobody documented.

The metamod architecture: WinUI apps over a custom runtime

The technical section explains what Rebound actually is, and the answer is that it is a metamod rather than a collection of themes and tweaks.

Rebound as a whole is a Windows 11 metamod: a collection of mods that rely on a custom runtime and environment to function. Every primary application in Rebound is UWP or WASDK with WinUI 2 or 3. More specifically, the majority of the user applications specific to Rebound consist of UWP XAML islands. The installers are WinUI 3, and the wrapper executables and custom DLLs are made on pure Win32. In short terms, the entirety of Rebound is WinUI, except for the wrapper executables and custom DLLs.

That last sentence is the one to hold on to, because it explains how the project keeps the Win32 system working. A WinUI application cannot replace a Win32 applet directly, so Rebound ships a Win32 wrapper that hosts the modern UI and communicates with the original system component underneath. The XAML island approach is what lets a WinUI 3 or 2 interface sit inside a host window.

The structure has a mandatory core and an optional layer. The core consists of multiple mandatory mods that are installed automatically via Rebound Hub when you enable Rebound, and these are critical for the metamod's functionality and cannot be turned off. Then there are the first-party mods that can be installed individually, and Rebound Hub, the dashboard application, is the only application that can run fully outside the Rebound environment itself.

The project's own documentation site has a page on how Rebound works behind the scenes, under the structure heading of the Rebound documentation.

The repository layout matches this structure. There is a src/ directory holding the applications, a build/ directory, an eng/ directory for the engineering scripts, docs/ with a docfx.json for documentation generation, an index.md and toc.yml for the documentation table of contents, a Rebound.slnx solution file, and a var/ directory.

What is included, and what the Hub adds

The app list is split into two groups, and the split tells you what is core to the metamod and what is a companion application.

Included in Rebound are the Disk Cleanup, Character Map UWP, Files, User Account Control Settings, About Windows (winver) and the Shell components, which covers the shutdown dialog and Run. These are the actual system apps being rewritten, and they are the ones tied to the custom runtime.

Featured in Rebound Hub are the optional ones: Ambie, Character Map UWP again, Fairmark, Files again, the Fluent Store, FluentHub, Fluetro PDF, PowerToys, Scanner, Screenbox, SecureFolderFS, WindowSill, Wino Mail and Wintoys. These are applications you can install from the Hub, and the list overlaps with the included set, which suggests the Hub version is a distinct, separately configurable build for the apps that appear in both.

The practical reading is that Rebound is two things at once. The metamod replaces a small number of Windows system applets, and Rebound Hub is a curated store of third-party and first-party applications that happens to share the same design language and installation flow.

That second role is why Rebound Hub is called out as the only application that can run fully outside the Rebound environment itself. If the runtime is broken, Hub is the thing you can still open.

The list also includes well-known projects such as PowerToys, which is not a Rebound project but is offered through the Hub, and the presence of niche tools like Screenbox and Wintoys suggests the Hub is intended to be a general Windows utility distribution with a consistent theme rather than a strict collection of Rewrites.

Installation and configuration, including the manual path

The normal path is an installer called Rebound Hub Installer.exe, which offers three options. Install puts Rebound Hub on the machine, and you then have to enable Rebound separately with each individual mod. Uninstall removes both Rebound and Rebound Hub. Repair attempts to repair everything currently installed from Rebound.

The manual path is for people who have compiled Rebound or who have the .msixpackage and .cer from the private testing channels, and the README states it in two steps. You install the certificate, Rebound.Hub[ver].cer, following a guide on installing an app package manually, and then you open Rebound.Hub[ver].msixbundle and install it. If the second step fails because the package is already installed, the fix is to uninstall the existing Rebound Hub and install the new one.

The private testing channels are worth noting. The artefacts needed for manual installation are not on the public releases page, so the documented manual route is for people inside the project's testing loop.

Configuration happens inside Rebound Hub. To enable Rebound you open the Hub, go to the Rebound tab and press the button that says Rebound is not enabled. After that you install each Rebound app you need, and to configure them you search in the navigation view or use the search bar to find the dedicated configuration page for each mod. General Rebound settings have their own page inside the Hub, and those settings apply to every Rebound app that supports them, or to Rebound as a whole.

The README also warns that Rebound will not work properly on Windows 10 or on debloated systems such as Tiny11. That is a hard constraint rather than a caveat, and it makes sense given the runtime dependency: a debloated system is by definition one that has had the components Rebound relies on removed.

The comparison table against classic Windows mods

The README includes a feature comparison against what it calls classic Windows mods, and the table is the project's clearest statement of why the metamod approach exists.

System-wide customization is marked as available in classic mods and not in Rebound, and the remark is that there are no msstyles modifications and no SecureUxThemePatcher used. This is the sharpest distinction in the table. Classic visual theming works by replacing system style resources, which touches everything on the system at once and is why those tools are considered risky.

Fully reversible changes go the other way, marked unavailable for classic mods and available in Rebound, with the remark that there is no need for system restore points. Compatibility with all software is also marked as a Rebound advantage, with the remark that it works with both Win32 APIs and Microsoft Store apps.

Windows Updates enabled is marked as a warning for classic mods and a check for Rebound, with the remark that updates are enabled by default, ensuring your system remains secure. That is the point of the whole design: the classic approach to theming Windows often involves disabling or deferring updates, because the update process overwrites the theme.

Backwards compatibility is another Rebound advantage, with the remark that Win32 system apps remain functional even if Rebound apps malfunction. That is what the wrapper executables buy, and it is a meaningful guarantee.

Two rows are hedged rather than binary. Safe for home users is marked unavailable for classic mods and available for Rebound, with the remark that while no mod is 100% safe, Rebound is generally safer than most mods. And additional features over Win32 apps is marked as a warning for classic mods and a check for Rebound, on the grounds that Rebound apps offer enhanced features compared to legacy Win32 applets.

Only one row is hedged in the other direction. Open source is marked as a warning for classic mods and a check for Rebound, with the remark that it is fully open-source, including the dedicated Rebound apps. The MIT licence in the repository and a THIRD_PARTY_NOTICES.md file are consistent with that.

Limits: beta status, an unsupported platform, and the cost of a custom runtime

The limits are visible and the README does not soften them.

The first is the maturity. The most recent releases are v0.0.10-Beta from 2025-07-18, v0.0.9-Beta from 2025-06-26 and v0.0.8-Beta from 2025-06-24. Every tag is a beta at version 0.0.x, and the README states plainly that v0.0.10 has known issues that will be fixed once v0.1.0 is released. The last push to the repository was on 2026-10-15, so work continues, but the version numbers are not reassuring if you are putting this on a work machine.

The second is the platform constraint. Rebound will not work properly on Windows 10 or on debloated systems like Tiny11. That narrows the audience to people on a supported Windows 11 build who have not stripped it down, which is a large constraint on an audience that is by definition interested in modifying Windows.

The third is that using it requires enough knowledge about Windows internals to navigate the project and debug on your own if an issue occurs, as the README puts it. Windows mods are layers of customization applied over an existing Windows installation and should be handled with care. That is a warning about the category, not just about this tool.

The fourth is the architectural consequence of a custom runtime. The metamod depends on a runtime and environment to function, with mandatory core mods that cannot be turned off, and the whole thing is layered over Windows components that Microsoft continues to change. Each Windows update is a compatibility event for a project whose version numbering has not yet reached 0.1.0. The backwards compatibility row in the comparison table, where the Win32 apps keep working, is the mitigation, and it is a real one, but it also means a system where two implementations of the same applet coexist.

The fifth is documentation. The README says the document is incomplete and that links to the official website may not point to valid locations, and it points at a separate documentation site for uninstalling, for compiling and for the structure. The installation details live across two places.

Rebound against theme tools and against rebuilding the apps yourself

Two comparisons make the choice clearer.

The first is against the classic theming tools, and the comparison table above is essentially that argument in the project's own words. A theme patcher replaces system style resources, which achieves a consistent look across every application on the machine, at the cost of touching the system globally, of requiring updates to be disabled or deferred, and of losing those changes on a restore point. Rebound takes the opposite approach. It leaves the system style resources alone and replaces individual applications with modern ones, so a failure is contained to that application, updates keep working, and the Win32 original remains underneath.

The cost is coverage. A style patcher changes everything at once. Rebound changes the applications it ships, which today is a short list of system applets plus whatever the Hub offers. If your complaint about Windows is the look of a hundred applications, Rebound does not address it.

The second comparison is against writing your own replacement application. The application list is a good demonstration that this is feasible for people who can: the source tree contains the first-party mods, the project is MIT licensed, and the repository has a solution file and an engineering directory, so the applications are buildable from source. Writing your own version of, say, the Run dialog or the shutdown dialog is a bounded task for someone who knows the Windows APIs.

The difference in approach is that Rebound's versions are built on WinUI and XAML islands inside the system, which means they can look and behave the way Windows 11 intends while still driving the underlying Win32 component. A standalone rewrite would have to reimplement the underlying behaviour as well, which is where the hard part is.

The deciding factor is probably the runtime. Rebound's Win32 wrapper executables and custom DLLs are what let it replace a system app without breaking the system, and that wrapper layer is the piece you would have to build and maintain yourself. If you want the whole set with the wrappers done, Rebound is the route. If you want one specific app, building it yourself is a smaller commitment than adopting a metamod.

Editorial conclusion

Adopt Rebound if you run Windows 11 and want the built-in system apps replaced with WinUI versions while keeping Windows Update and the underlying Win32 apps intact. Do not adopt it on Windows 10, on a debloated installation such as Tiny11, or on a machine you cannot restore. Verify first that your system meets the stated minimum requirements, that you have a restore path in place, and that the specific app you want to replace is one of the mods in the list rather than something you would have to build yourself.

Frequently asked questions

Official sources

1. IviriusCommunity/Rebound on GitHub
2. License: MIT
3. Project website
4. README
5. Releases