Java didn’t come with a regex package until Java 1.4, so early programmers had to do without regular expressions. Over time, many programmers independently developed Java regex packages of varying degrees of quality, functionality, and complexity. With the early-2002 release of Java 1.4, Sun entered the fray with their java.util.regex package. In preparing this chapter, I looked at Sun’s package, and a few others (detailed starting on page 372). So which one is best? As you’ll soon see, there can be many ways to judge that.