It is an open source project I started in 2004 before joining Microsoft and I continue to maintain it in my free time.
NLog is a free logging platform for .NET with rich log routing and management capabilities. It makes it easy to produce and manage high-quality logs for your application regardless of its size or complexity. NLog is my sole responsibility and it is not affiliated, endorsed nor supported by Microsoft Corporation.
For more information about the project, go to http://nlog-project.org/