I’ve begun to notice that there’s somewhat of a gradual move away from MSI-style installers. This is an interesting change considering for a number of years now I’ve been a keen proponent of creating an MSI to package up your software and drive the installation process during deployment.

MSI (Windows Installer – previously Microsoft Installer) started life as the Office 2000 installer. Office was (and still is) quite a large and complex piece of software and I guess the development team realised they needed a slightly more reliable way to install all the bits in the right places.

This then evolved into a more general-purpose installer technology and was finally built right in to Windows itself as the preferred way to install applications and services.

So what’s changed?

MSI is great if you just need to install a single instance of an application. It is possible to handle multiple instances – for example SQL Server. If you’ve ever installed SQL you’ll know that you can use the setup program to install multiple instance of SQL Server. I recently learned through a question posed to a Reddit AMA that they use ‘Transforms’ for this. It is possible, but not super easy.

Then there’s Nano – Nano Server to be precise. This is the new super cut-down, minimalist edition of Windows Server, and one of the things that has been left out to keep it as lean as possible is MSI support. To build software for Nano, you’ll be packaging it up in an ‘appx’ file (essentially the same package used for Windows 8/10 UWP).

So who’s changed?

I noticed that JetBrains went to a non-MSI installer with their ReSharper 9.x release. They were already using NuGet packages for managing extensions. I think they’ve kind of gone the whole way with their installer now.

It also appears that Visual Studio “15” (not to be confused with the current 2015 release which is version 14) is moving to a non-MSI installer as part of reducing the install process.

ASP.NET for a while now has had the ‘msdeploy’ packaging. It’s what is used when you choose ‘Publish’ from the context menu in Visual Studio.

So what now?

MSI still has a role, especially for traditional server deployments, but if you want to support deployments to Nano then you’ll need to look at appx. If you have a desktop app that you’d like to feature in the Windows Store, then appx is also a requirement.

There’s currently a couple of options if you want to move towards appx deployments:

Project Centennial – aka the Desktop Converter for Win32 or .NET 4.6.1 apps. This is currently in preview (and requires that you run on a preview release of Windows 10).

WiX AppX Extension – a commercial product created by some of the main WiX developers that lets you leverage your existing WiX projects to produce an Appx package.