Industrial Strength Windows Installer XML

IsWiX is an open source, extensible Windows Installer XML document editor that enables non-setup developers to easily collaborate with setup developers

IsWiX is hosted at GitHub.

Vantive XML Express for .NET

Vantive XML Express for .NET (VXEN) is a .NET based SDK for interacting with the Vantive XML Express API.

VXEN is hosted at GitHub and is available as a Nuget package.