An Early website HandHelds.org that was active in the days before the wave of Portable Devices you see today. 2003-2004. Advanced Portable devices are now in everybody's hand.
"At the hardware level, we embrace any device that can reasonably be considered a handheld computer. We are product and architecture neutral. Software development on an open-ended set of handheld computers is welcome within the context of our group and our website. These projects include both individual efforts and work sponsored and organized by individuals, groups or companies. "
"At the operating system level, our focus is on "Unix-like" systems, including Linux and the various flavors of BSD Unix (FreeBSD, NetBSD, OpenBSD, etc.). Among these alternative operating systems, healthy and energetic competition results in better software for everyone."
My Notes -
I feel HandHeld Computers range from Advanced Calculators to Laptops, The have to be driven by batteries, charged by Mains, Solar, Wind Power or Dynamos. They can be carried around by a single human being or may be part of a Vehicle he uses. It can have a Wireless Web Connectivity or may just be a passive multimedia or games player.