There’s change in the air for those of us who design interfaces for a living. Where once we could choose only between designing in code or designing in Photoshop, we’re now seeing at least one or two promising if still nascent alternatives. Last month I wrote about Bohemian Coding’s Sketch, which I now use more frequently than Photoshop. (.Net Magazine also did a short interview with me about Sketch.)

Having one viable replacement is almost more than any of us could have hoped for five or ten years ago, but here comes Macaw, still in previews but propitious all the same. It bills itself as a “code-savvy web design tool” and like Sketch it brings a refreshingly relevant approach to designing interfaces. A few of its many slick new features jumped out at me as I watched its longish sneak peek video: built-in lorem ipsum generation; grid-based nudging of elements; and oh yeah generating real code as you’re designing. If they work as advertised, all three look like genius.

I’m really happy these contenders are emerging today, but why did it take so long for this to happen? Technologically, there seems little about either Sketch or Macaw that couldn’t have happened five years — if not a decade — ago. The answer, I think, is simple: the Mac App Store, which has leveled the playing field for independent developers — if not completely, then significantly. It might have been possible to build Macaw or Sketch before, but the Mac App Store gives these new players a visibility and distribution channel that’s invaluable when indie developers go up against entrenched players.

You can watch the Macaw preview here.