Skymu is a modern multi-platform IM client that looks like classic versions of Skype, with skins perfectly resembling Skype 4, 5, 6, and 7. Officially supported messaging services include Matrix, Tox, MSNP11, and some other platforms.
For this guide, you will need Git for Windows, Visual Studio 2019 (or newer) and NSIS 3 (or newer). Support will not be provided if older build tools are used.
- Download Git for Windows and install. For the default editor, we recommend you select Notepad (or Notepad++, etc. if you have it) instead of Vim, unless of course you feel like dedicating a few days to learning how to use Vim. Stick with the default options for the other things the installer asks you.
- Download Visual Studio 2019 (recommended) or download Visual Studio 2026. Select the ".NET desktop development" workload in the installer.
- Download NSIS
A plugin development guide is available on the website: https://www.skymu.app/wiki/yggdrasil
Open Command Prompt, navigate to the folder you want Skymu in, and run git clone https://github.com/TheSkymuTeam/Skymu.git to download the repository.
Open the Skymu.sln solution file with Visual Studio.
Select the "Debug" configuration in the action bar.
If you want to change the internal name (recommended to avoid conflicts with your existing Skymu installation!) or version, go to Skymu/Skymu/App.xaml.cs in the Solution Explorer pane, click to open the file, and then edit these values. Note that changing this will make the updater stop working.
Press Ctrl + Shift + B to build the solution for the first time, or click "Build Solution" in the menu bar under "Build". Notice for advanced users: Both .NET Core and .NET Framework builds of Skymu are built at the same time and can be found in /Skymu/bin/Skymu.Core and /Skymu/bin/Skymu.Legacy respectively.
Click the play button on the action bar to run your copy of Skymu.
If you are encountering conflicts after making your changes, click "Rebuild Solution" to clean cache and build from scratch.
Select the "Release" configuration in the action bar and build Skymu in Visual Studio.
Navigate to the NSIS folder, right-click on the type of installer you want to build, and then click "Compile NSIS Script". SkymuSetup.nsi is for the standard installer, SkymuBetaSetup.nsi is for the beta installer, both are functionally the same and differ only in appearance.
The NSIS compiler will run. After it's finished, the output log will turn green and Skymu Installer.exe will show up in the folder; click "Test Installer" to run it.
| Software | Author | License | Used in | Source code |
|---|---|---|---|---|
| BouncyCastle.Cryptography | Legion of the Bouncy Castle | Apache-2.0 AND MIT | Yggdrasil, Discord | Repo |
| c-toxcore | The TokTok team | GPL v3 | Tox | Repo |
| CommunityToolkit.Mvvm | Microsoft | MIT | Skymu | Repo |
| Concentus | Logan Stromberg | BSD-3-Clause | Discord | Repo |
| Google.Protobuf | BSD-3-Clause | Discord | Repo | |
| libopus | Xiph.Org and others (including Skype Limited) | BSD 3-Clause | Tox | Repo |
| libsodium | jedisct1 | ISC | Tox | Repo |
| Markdig | Alexandre Mutel | BSD-2-Clause | Skymu | Repo |
| Microsoft.CSharp | Microsoft | MIT | Yggdrasil, Discord | Repo |
| Microsoft.Data.Sqlite | Microsoft | MIT | Skymu, Skype DB Browser | Repo |
| NAudio.Core | Mark Heath | MIT | Stub, Tox, Discord | Repo |
| NAudio.WinMM | Mark Heath | MIT | Stub, Tox, Discord | Repo |
| NLayer.NAudioSupport | Mark Heath | MIT | Stub | Repo |
| pthreadVC3 | rosspjohnson | Apache-2.0 | Tox | Sourceforge |
| QRCoder | Shane32 | MIT | Skymu | Repo |
| SharpZipLib | ICSharpCode | MIT | Discord | Repo |
| System.Net.WebSockets.Client.Managed | PingmanTools | MIT | Skymu, Matrix, Discord | Repo |
| System.Runtime.CompilerServices.Unsafe | Microsoft | MIT | Skymu | Repo |
| System.Text.Json | Microsoft | MIT | Skymu, Matrix, Discord | Repo |
| System.Threading.Channels | Microsoft | MIT | Skymu, Stub, Tox, Discord | Repo |