There are a number of good programs available, but I have settled on Editra, because it’s free and available Mac, Windows, and Linux/Unix. You can download a copy by visiting http://editra.org and selecting the Download link toward the top left of the page, where you can also find the documentation for it.
As you can see from Figure 2-20, Editra highlights the syntax appropriately to help clarify what’s going on. What’s more, you can place the cursor next to brackets or braces and Editra will highlight the matching pair so that you can check whether you have too many or too few. In fact, Editra can do a lot more than this, which you will discover and enjoy as you use it.
Again, if you have a different preferred program editor, use that—it’s always a good idea to use programs you’re already familiar with.