PicoLisp is quite different from other Lisps. The main reason is its focus on
data.  PicoLisp has one single internal data type: The "cell".  On the language
level it has only three data types: Numbers, symbols and cons pairs. They are
all built from cells.  What may sound like a restriction is actually a big
advantage. The simple internal structure results in high start-up and execution
speeds. Cells can be manipulated freely in any conceivable way, giving full
control to the programmer.