We covered some of the proprietary issues involvingthe Netscape and Internet Explorer browsers. While an awareness of the featuresand quirks of each major browser and version is required to write well-behaved code, it is not a sufficient condition. You need to be able to apply what you know in an effectivemanner in order to accommodate the needs of your users, fellow programmers, andfuture script maintainers. In this chapter we bring to a close our discussion of JavaScript by highlighting some recommended practices for and salient issues regarding JavaScript in the “real world.”Our focus is on errors and debugging as well as on writing robust JavaScript that utilizesdefensive programming techniques. We also touch on some distribution issues, such asprotecting your code and decreasing its download time, and discuss where JavaScriptfits into the “big picture” of the Web. The discussion in this chapter condenses manyyears worth of programming experience into a few dozen pages, so that developers—new ones in particular—can save themselves and their users some headaches by carefulconsideration of the content presented here.