Home page: http://sourceforge.net/projects/wix/
License: Common Public License
The founding author: Rob Mensching, left MS at December 2006, to which relates his last message on an msdn blog: http://blogs.msdn.com/robmen/default.aspx. His current blog is: http://robmensching.com/blog/. Provides very interesting views on open source in MS world and open source in common. In particular this entry somehow linked my mind to Spring.NET, NHibernate, NDoc (dead).
The tutorial: http://www.tramontana.co.hu/wix/index.php
John Robbins' blog filtered on WiX: http://msmvps.com/blogs/installsite/archive/tags/WiX/default.aspx
Activity: By eyeballing of the source it seems that there is only one active member now (Benxing).