MacinCloud
Get your own Macintosh Server in the Cloud
MacinCloud is a cool service that let's you have access to a real Macintosh. While it may seem silly if you own one, but if your doing some development work and need to make sure the application works in different environments it can be very useful.
Each box comes pre-installed with various developer tools including the latest Xcode, Microsoft Visual Studio for Mac with Xamarin components and more.
MacinCloud can be useful when testing software and figuring out why some applications are working and not working in different environments.
Description from the Website
MacinCloud provides managed and dedicated cloud Mac servers, hosted private cloud solutions and DevOp pipelines. Users can access on-demand Mac servers for app development, Mac tasks, and enterprise builds. All of our plans and solutions are backed by genuine Mac hardware hosted in 7 professional data centers around the globe.
This isn't a free service, you have to pay to access the boxes - which can be a lot cheaper than straight out owning your own box at a colocation center.