OpenJMS, a seven-year-old open-source middleware product based on Sun Microsystems Inc.'s Java Messaging Service, also got low ratings. But Tim Anderson, an Australian developer who is one of the OpenJMS's project leaders, said he has "no criticism of the accuracy. OpenJMS has been in a holding pattern for some time due to family and work commitments. There will be a beta released in the next few months."

Other open-source developers, however, disputed Optaros' ratings and questioned the consultancy's objectivity because of marketing or reseller relationships it has with certain open-source vendors.

Jeremy White, CEO of St. Paul, Minn.-based CodeWeavers Inc., is one such critic. His company sells the CrossOver family of software that has long let users run Windows software on computers running Apple Inc.'s Mac OS X or the Linux OS.

CrossOver is based around the open-source Wine project, for which White is one of the chief maintainers. Optaros gave Wine only a 2 out of 5 for the product's maturity, and an overall score of 1 for enterprise readiness.

White takes "serious issue" with those ratings. "We've had a professional product out around Wine for four years now, and Wine has been around for 13," he said. "I'm quite offended by the 1 for enterprise readiness...given that we have a fairly substantial number of large enterprises using our product, some on rather large scales [thousands of seats]. I think the real-world evidence backs my claim."