PDA Architecture
Many PDAs run using a variation of the ARM architecture (usually denoted by the Intel XScale trademark). This encompasses a class of RISC microprocessors that are widely used in mobile devices and embedded systems, and its design was influenced strongly by a popular 1970s/1980s CPU, the MOS Technology 6502.PDA OS
The currently major PDA operating systems are:Palm OS - owned by PalmSource
Windows Mobile Professional and Classic for use on Pocket PCs, (based on the Windows CE kernel) - owned by Microsoft
BlackBerry OS - owned by Research In Motion
Many operating systems based on the Linux kernel - free (not owned by any company) These include
Familiar (comes in three flavours: GPE, Opie and barebone)
OpenZaurus (for Zaurus PDAs)
Intimate (for PDAs with an exceedingly large amount of memory)
Symbian OS (formerly EPOC) owned by Motorola, Panasonic, Nokia, Samsung, Siemens and Sony Ericsson