A recent study of open source software by Coverity, Inc showed that Perl's quality is impressively free of bugs and defects. Ben Chelf, Coverity's CTO, commented that "of the LAMP stack, Perl had the best defect density, well past standard deviation and better than the average."
Perl's extensive quality control process, which uses over 160,000 individual cases, tested nightly on dozens of architectures and operating systems as well as every time a user compiles Perl from source, is key to its success.
Although Coverity's static source code analysis indicated a small number of potential glitches in Perl's half-million lines of code, the core development team quickly solved them. At the same time, at least one bug in Perl reported by Coverity's Prevent product was actually a bug in Prevent. However, as Nicholas Clark notes, "Coverity found bugs that had escaped the detection of earlier tools used to refine the Perl source code, tools such as Purify, The Third Degree and Valgrind."
Andy Lester of the Perl Foundation said, "As a core Perl developer, I'm glad to have Coverity working with us on quality. As a Perl fan, I'm glad to see Coverity get the word out about my favorite language."
The fixes suggested by Coverity will be included in the forthcoming 5.10 stable release of Perl and are already available in the development 5.9 branch. Many fixes will also be backported to the 5.8 series.
The Perl Foundation is dedicated to the advancement of the Perl programming language through open discussion, collaboration, design, and code. The Foundation is a unit of the Yet Another Society (YAS), a non-profit, 501(c)(3) organization based in Holland, Michigan.