Euphoria

puts(1,"Hello, World!")

function factorial(integer n)
    if n = 0 then
        return 1
    else
        return n*factorial(n-1)
    end if
end function

for n = 0 to 16 do
    printf(1,"%d! = %d\n",{n,factorial(n)})
end for

function fib(integer n)
    sequence f
    if n = 1 then
        return {1}
    elsif n = 2 then
        return {1,1}
    else
        f = fib(n-1)
        f = append(f, f[$-1] + f[$])
        return f
    end if
end function

print(1,fib(16))

include get.e

atom A
atom B, C
atom D

A = prompt_number("A=", {})
if A = 0 then
    puts(1,"Not a quadratic equation.\n")
else
    B = prompt_number("B=", {})
    C = prompt_number("C=", {})
    D = B*B - 4*A*C
    if D = 0 then
        printf(1,"x = %g\n", -B/2/A)
    else
        if D > 0 then
            printf(1,"x1 = %g\n", -B+sqrt(D)/2/A)
            printf(1,"x2 = %g\n", -B-sqrt(D)/2/A)
        else
            printf(1,"x1 = (%g,%g)\n", {-B/2/A, sqrt(-D)/2/A})
            printf(1,"x2 = (%g,%g)\n", {-B/2/A, sqrt(-D)/2/A})
        end if
    end if
end if

integer f
f = 1
for n = 0 to 15 do
  printf(1,"%d! = %d\n",{n,f})
  f *= n+1
end for