 Forth is a simple yet extensible language ; its modularity and <unk> permit the writing of high @-@ level programs such as CAD systems . Forth has been used successfully in large , complex projects , while applications developed by competent , disciplined professionals have proven to be easily maintained on evolving hardware platforms over decades of use . Forth has a niche both in astronomical and space applications . Forth is still used today in many embedded systems ( small computerized devices ) because of its portability , efficient memory use , short development time , and fast execution speed . It has been implemented efficiently on modern RISC processors , and processors that use Forth as machine language have been produced . Other uses of Forth include the Open Firmware boot ROMs used by Apple , IBM , Sun , and <unk> XO @-@ 1 ; and the <unk> @-@ based first stage boot controller of the FreeBSD operating system . 
