Ask HN: What tools helps you try new tech business ideas quickly?

I think trying a lot of different ideas is probably single most important factor in stumbling on success in business as long as execution does not take lot of time/money/effort.

When you are not building something to scale but simply to test your assumptions and market the choice of tools could be very different.

What are the best tools/languages/platforms/techniques to try new ideas quickly? I am open to any and all ideas out there.