The project page has moved to http://ilmerge.xpdm.us

Interested in using ILMerge during an automated build? ILMerge Tasks containts two buildable projects that will allow you to access ILMerge as a task from both MSBuild and NAnt. It even includes a post-build event that merges ILMerge and the task dll so that you can use the task without ILMerge.exe being present.

ILMerge is not licensed for redistribution, so you will need to obtain it from Microsoft here.