The ATX standard has changed very little in the last 15 years, which means some rather old computer cases can still accept new motherboards, as long as you also replace the power supply.
The bad news, as I stare at the case that once housed a Micron Client Pro 766 Xi (a 266 MHz Pentium II that was state of the art in 1997) is that front-mount USB ports were unheard of in those days, as were digital camera memory cards. Instead, machines of that era used obsolete floppy and Zip disks for removable storage. They also typically had more 5.25″ bays than we need today. When CD burners cost $400, most of us kept a reader in as well, to avoid wearing out expensive burners prematurely.
David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.