The Linux Standard Base set of standards has reached "critical mass" with the support of Computer Associates, according to the Free Standards Group's (FSG) executive director Jim Zemlin.

As the highest-profile software vendor supporter to date, the addition of CA brings LSB "to the tipping point", said Zemlin.

The LSB is a set of standards designed to give different Linux distributions as much application compatibility as possible, and combat the fragmentation that has made Unix relatively expensive for software vendors to support. An LSB-certified application should be able to run on any LSB-compliant distribution on a particular hardware platform, porting to other hardware types is designed to be straightforward.

The addition of new supporters, including CA, was announced this week along with the availability of the LSB 3.0, which makes more functionality available for certification, and has signed up more Linux vendors.

A standards project like the LSB is important because of Linux's decentralised development model, according to the operating system vendors such as Red Hat and Novell that certify to the standard. CA said the project is just as important to application vendors, who want to avoid an expensive porting process for each Linux distribution.

"The effective standardisation of Linux implementations is essential for the growth of the market and for organisations to obtain maximum value from their technology investments," said CA senior vice president and senior technical advisor Sam Greenblatt.

The FSG's Zemlin said of CA's support: "We've reached the tipping point with the LSB. If you're an application developer targeting the Linux opportunity, your job just got a lot easier."

The LSB 3.0 adds an updated application binary interface (ABI) for C++, easing application portability. The standard is more closely aligned with the POSIX industry-standard portability guidelines, and adds a Realtime library, allowing applications to use POSIX clocks and POSIX shared memory. The hardware architectures supported are IA32, IA64, PPC32, PPC64, S390, S390X and X86_64.

Red Hat, Novell, the Debian Common Core Alliance (DCC Alliance) and Asianux have all said they are certifying to the new standard, with Mandriva going through the certification process.

The DCC Alliance was formed over the summer to promote an enterprise-friendly, Debian-based distribution closely tied to the LSB. The project has delivered early beta-test versions, with a final common core expected in October.

"The DCC Alliance was formed because enterprise clients were demanding a single Debian Linux standard, and the LSB is crucial to our success," stated Ian Murdock, Debian founder, Progeny chariman and leader of the DCC Alliance.

The group includes Debian-based distributors such as Linspire, LinEx, Sun Wah, UserLinux and Xandros. It doesn't, however, include the most successful Debian-based project of all - Ubuntu, whose popularity has made it a de facto standard since its launch by South African dot-com billionaire Mark Shuttleworth in 2004.