[nvrspyx]

It's not. It's an open source project (aka owned by no one) that started at Microsoft. The person who created WiX left Microsoft to create Firegiant, which is the primary contributor to its continued development and maintenance.

[bedatadriven]

Open source does not mean "owned by no one". It means the owner or owners have licenced their intellectual property to you under the terms of an oss license.