A web installer is a bootstrapper that downloads some or all of its resources from the web during installation. This way, the initial download of the bootstrapper is faster, since its file size is much smaller. The main portion of it is hosted online where it's only downloaded when you need it. The disadvantage is that end users will need an Internet connection when they run the installer. However, in many cases, that's a small price to pay.

In this recipe, we'll need to have our resources hosted online. When I say resources, I'm talking about MSI packages, other executable installers, and patch files. To give you an idea about how it would work, we'll use an MSI file that's already on the Web: the Node.js installer.