I have a first gen Mac Mini (2006) that I use for Mac specific software on occasion. It's so old at this point that I can't install most new software, webpages won't load because the browser is so outdated, etc. With a few modifications, I can get OS X 10.7 Lion installed and eke out a few more years (hopefully).
Mac mini (Late 2006)
OS X 10.7 Lion
CPU Upgrade Options for 2006 and 2007 Mac minis
dosdude1's Personal Web Server (OS Patcher)
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