Operating System

time - number of seconds since a fixed point in the past
date - current year, month, day, hour, minute, second etc.
command_line - command-line used to run this program
getenv - get value of an environment variable
system - execute an operating system command line
system_exec - execute a program and get its exit code
abort - terminate execution
sleep - suspend execution for a period of time
platform - find out which operating system we are running on
machine_bits - determine 32 or 64 bit operation. (likewise machine_word, as documented on the same page)
include_paths - returns a list of include paths
get_proper_dir - obtain the full path of a file or directory
get_proper_path - obtain the actual longname and full path of a file or directory