Having installed Caldera once before, the speaker taught us that you should NOT use the Dynamic Drive Overlay, and that it is a good idea to defrag your hard drive first, as well as take an inventory of your computer before starting. Linux is, indeed, free. RedHat is reported to be somewhat more complicated to install. Actually the Caldera install uses the familiar Windows install boxes. Overall, it took slightly more than an hour to install.
Open source is great for two reasons.
First, no company can match the resources of hundreds or thousands of people working to improve some software. Thus, Linux is being improved daily, and almost all of the improvements are free or very low cost. The second reason is that lots of people understand it, and thus can answer your questions online. Windows does not like to run continuously. Unix, including Linux, computers were designed to run and run and run for months and months.