Use the Apple Mac mini server as a powerful and cheap part of a server cluster. Whether you are a developer or need to analyse lots of data: a Mac mini server is more powerful than you might think. Equipped with a Quad Core processor and up to 16GB of RAM memory, perhaps combined with lightning fast SSD-disks your Mac mini will turn into a fast work horse. In comparison to traditional 1U or blade servers, the Mac mini is mostly cheaper in both purchase and recurring colocation costs due to its low energy consumption and small form factor.
You’re absolutely free to choose the software and OS you want to run on a Mac mini. Think of a Mac mini running VMWare ESXi, Windows Server or a Linux-distribution like Ubuntu. This way you’re able to create a flexible cluster (web, database, computing, Remote Desktop, etc.)