If you want to try a secondary OS without installing it alongside your main OS, you can use virtualization software like VirtualBox or VMware to run it in a virtual machine on your host system. This allows you to test and use the OS without making permanent changes to your primary setup.
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VirtualBox is an x86 and AMD64/Intel64 virtualization product. It is the only professional solution available for free as Open Source Software under the GNU GPL V2 license.
VMware Player is a free virtualization product for personal use, provided by VMware, Inc. It can run existing virtual appliances and create new virtual machines.