Source code in the livecode programming language

// recursive
function factorialr n
    if n < 2 then 
        return 1
    else
        return n * factorialr(n-1)
    end if
end factorialr

// using accumulator
function factorialacc n acc
    if n = 0 then
        return acc
    else
        return factorialacc(n-1, n * acc)
    end if
end factorialacc

function factorial n
    return factorialacc(n,1)
end factorial

// iterative
function factorialit n
put 1 into f
    if n > 1 then 
        repeat with i = 1 to n
            multiply f by i
        end repeat
    end if
    return f
end factorialit