The review compared version 2.1 of the Apache Web server software, which is used to house Web sites, with several commercial packages that handle the same chores. Reasoning, a company whose business is analyzing code quality, compared the recently released version with code of competitors at a similar stage of development.
The study found 0.53 defects per thousand lines of code for Apache, compared with 0.51 for the commercial software, on average.
The comparable defect rate indicates that open-source software starts out as raw as proprietary software, but Reasoning said that ultimately open-source software has the potential to exceed proprietary software in quality. That's significant given the increasingly widespread use of open-source software such as Linux, OpenOffice desktop suite and the MySQL database.
"The open-source code seems to start at the same defect rate for early commercial code as well," Jeff Klagenberg, director of project management, said in an interview. "Over time, it can gain higher levels of quality. That appears to be because of the natural inspection process inherent in open source."
The earlier study praised Linux for the quality of the component that handles the TCP/IP networking that underlies the Internet and many home and corporate networks. That code had a defect rate of 0.1 per 1,000 lines of code and was a more mature section of code.
Reasoning next is studying Tomcat, an Apache module that lets Web servers run Java programs, said Tom Fry, Apache's director of marketing. The company plans to release that study in about two weeks, he said.