public static void Main(string[] args)
{
var featureA = new Feature("Feature A", "Feature A description");
var featureB = new Feature("Feature B", "Feature B description");
var complete = new Feature("Complete");
complete.Add(featureA)
.Add(featureB);
var project =
new Project("MyMergeModuleSetup",
new Dir(@"%ProgramFiles%\My Company",
new File(featureA, @"Files\MainFile.txt"),
new Merge(featureB, @"Files\MyMergeModule.msm"),
new Merge(featureB, @"Files\MyMergeModule1.msm")));
project.DefaultFeature = complete;
project.UI = WUI.WixUI_FeatureTree;
project.InstallerVersion = 200; //you may want to change it to match MSM module installer version
project.PreserveTempFiles = true;
project.BuildWxs();
}