This got me thinking about the benefits of using third-party libraries in our own code.  Why should a program depend on so many external modules when it could implement what it needs itself?

The answer, in one word, is “Testing.”  A well-written piece of software isn’t considered complete if it doesn’t have well-documented tests that exercise every part of the program.

There are many common tasks that most programs perform – such as reading configuration food, performing date arithmetic and writing to log files.  Every popular language has third-party libraries that perform these tasks correctly and reliably.  If I were to try to duplicate them, it would almost certainly result in inferior code; the mature libraries have had the benefits of extensive testing as well as enhancements and fixes of bugs reported by users.  Using third-party software allows me to focus on my program and what makes it unique.

Perl can be a little stubborn, sometimes.