Starry, 191 188 186 182 172 bytes

 + + +* + * + + +* + .* + + +* * + +* . + + . + . + + + +* + .  + +* +* + . + + * +* . +* + * . + .* . . . + * . 

Line Explanation Stack Out ------------------------------------------------------------------------------------- + + +* + * + Push 3 and 36, dup [3 36 36] + +* + . Dup, x2, dup, print [3 36 36 72] H * Add [3 36 108] H + + +* * + Dup, sub 8, dup [3 36 108 100 100] H +* . Add 1, print [3 36 108 100] He + + . Swap, dup, print [3 36 100 108] Hel + . Dup, print [3 36 100 108] Hell + + + Dup, push 3, dup [3 36 100 108 108 3 3] Hell +* + . Rot 3, add, dup, print [3 36 100 108 3 111] Hello + +* +* + . Push 44, dup, print  [3 36 100 108 3 111 44] Hello, + + * +* . Print 32 [3 36 100 108 3 111 44] Hello, +* + * . Double, sub 1, print [3 36 100 108 3 111] Hello, W + . Dup, print [3 36 100 108 3 111] Hello, Wo * . Add, print [3 36 100 108] Hello, Wor . . Print, print [3 36] Hello, World + * . Swap, sub, print [] Hello, World! 

Starry, 191 188 186 182 172 169 bytes

 + + +* + * + + +* + .* + + +* * + +* . + + . + . + + + +* + . + + * +* + . + + * +* . +* + * . + .* . . . + * . 

Line Explanation Stack Out ------------------------------------------------------------------------------------- + + +* + * + Push 3 and 36, dup [3 36 36] + +* + . Dup, x2, dup, print [3 36 36 72] H * Add [3 36 108] H + + +* * + Dup, sub 8, dup [3 36 108 100 100] H +* . Add 1, print [3 36 108 100] He + + . Swap, dup, print [3 36 100 108] Hel + . Dup, print [3 36 100 108] Hell + + + Dup, push 3, dup [3 36 100 108 108 3 3] Hell +* + . Rot 3, add, dup, print [3 36 100 108 3 111] Hello + + * +* + . Dup, //5*2, dup, print [3 36 100 108 3 111 44] Hello, + + * +* . Print 32 [3 36 100 108 3 111 44] Hello, +* + * . Double, sub 1, print [3 36 100 108 3 111] Hello, W + . Dup, print [3 36 100 108 3 111] Hello, Wo * . Add, print [3 36 100 108] Hello, Wor . . Print, print [3 36] Hello, World + * . Swap, sub, print [] Hello, World! 

(Edit: Explanation slightly outdated, new version now uses the fact that H (72) = 2*36 and l (108) = 3*36)

Line Explanation Stack Out ------------------------------------------------------------------------------------- + + +* + * + Push 3 and 36, dup [3 36 36] +* . Double and print [3 36] H  + +* + * + Push 100 and dup [3 36 100 100]  H +* + . Add 1, dup, print [3 36 100 101] He +* + . Add 7, dup, print [3 36 100 108] Hel + . Dup, print [3 36 100 108] Hell + + + Dup, push 3, dup [3 36 100 108 108 3 3] Hell +* + . Rot 3, add, dup, print [3 36 100 108 3 111] Hello + +* +* + . Push 44, dup, print [3 36 100 108 3 111 44] Hello, + + * +* . Print 32 [3 36 100 108 3 111 44] Hello, +* + * . Double, sub 1, print [3 36 100 108 3 111] Hello, W + . Dup, print [3 36 100 108 3 111] Hello, Wo * . Add, print [3 36 100 108] Hello, Wor . . Print, print [3 36] Hello, World + * . Swap, sub, print [] Hello, World! 

Line Explanation Stack Out ------------------------------------------------------------------------------------- + + +* + * + Push 3 and 36, dup [3 36 36]  + +* + . Dup, x2, dup, print [3 36 36 72] H *   Add  [3 36 108]  H +   + +* * + Dup, sub 8, dup  [3 36 108 100 100] H +* .  Add 1, print  [3 36 108 100] He + + . Swap, dup, print  [3 36 100 108] Hel + . Dup, print [3 36 100 108] Hell + + + Dup, push 3, dup [3 36 100 108 108 3 3] Hell +* + . Rot 3, add, dup, print [3 36 100 108 3 111] Hello + +* +* + . Push 44, dup, print [3 36 100 108 3 111 44] Hello, + + * +* . Print 32 [3 36 100 108 3 111 44] Hello, +* + * . Double, sub 1, print [3 36 100 108 3 111] Hello, W + . Dup, print [3 36 100 108 3 111] Hello, Wo * . Add, print [3 36 100 108] Hello, Wor . . Print, print [3 36] Hello, World + * . Swap, sub, print [] Hello, World! 

Starry, 191 188 186 182 174 bytes

 + + +* + * + + +* + .* + +* +  * + +* . + + . + . + + + +* + . + +* +* + . + + * +* . +* + * . + .* . . . + * . 

Starry, 191 188 186 182 172 bytes

 + + +* + * + + +* + .* + + +* * + +* . + + . + . + + + +* + . + +* +* + . + + * +* . +* + * . + .* . . . + * .