The Linux Foundation - the non-profit consortium that gives Linus Torvalds his paycheck and facilitates the growth of Linux and Linux standards - has announced the first beta of the Linux Standard Base 4.0.

There are many Linux variants, and they use different kernel releases and software libraries, depending on the technical preferences of the people putting together the distros. Variety may be the spice of life, but it can cause compatibility issues if it is taken too far, and the LSB effort has established many years ago to provide a consistent set of specifications that allow the many distros to remain compatible despite their individual choices and, using LSB tools, to test operating system and application code to ensure that they adhere to the specs.

The Linux Foundation itself was formed in January 2007 to help remove some redundancies in the Linux development effort and to provide a single point of contact for those contributing to the Linux cause. It does not, however, directly steer the development of Linux, says Ted T'so, chief platform strategist and a fellow at the Linux Foundation who is also the maintainer of the ext4 file system project related to Linux.

This is a common misconception, apparently. The Linux Foundation is the result of the merger of Open Source Development Labs, an industry consortium established in 2000 by key IT vendors who wanted to get a hand in steering the development of Linux and other open source programs, and the Free Standards Group, the home of the Linux Standards Base, a specification that wants to keep Linux implementations from forking and to make it easier to ensure applications run across various Linuxes.

With the LSB 4.0 spec, a new tool is going to make it easier for independent software vendors to see just how portable their applications are thanks to the revised Linux Application Checker. The new checker draws upon a framework created by researchers the Russian Academy of Sciences that can peer into application binaries and determine how it will run on LSB-certified Linuxes. LSB 4.0 also has a specification for shell scripts that is intended to let scripts run across any of the popular shells out there, and it has a script checker that will show which scripts in a distro won't work if a different shell is used.

With LSB 4.0, the software development kit is being decoupled from the specification, which means the SDK can evolve on its own schedule. This also means the SDK is designed to build applications that adhere to LSB 3.0, 3.1, 3.2, or 4.0 specs. In other words, it's not tied to a specific LSB release level.

According to T'so, all of the current Linux distributions are certified to the LSB 3.1 or 3.2 spec, but only a handful of Linux applications themselves have been certified. "In the application space, people tend to want to use the very latest libraries," explains T'so. That means that application makers are often ahead of the LSB, which by its nature has to take a slower, more conservative approach since its goal is Linux compatibility, not speed or some other attribute of an application.

LSB compliance is, nonetheless, used as a proxy for application compliance, in that if a Linux application runs on one distribution, a vendor can be "reasonably confident" that it will be compatible with another LSB-certified Linux distro at the same compliance level. But T'so and his compatriots at the Linux Foundation have higher hopes for LSB 4.0.

"LSB 4.0 will be the first release where we have a critical mass of libraries together, which means more application vendors can and will certify."

T'so says that the Linux Foundation hopes to have LSB 4.0 finalized by the end of the year and that as the major Linux distros put out their service packs and updates over the next two quarters or so, they will update their certifications for the spec.

Once LSB 4.0 is out, a dozen key applications will be certified right out of the box, and T'so says another 75 or so applications will be able to be certified with a minor change, such as a recompile or the move to a more modern server platform. In total, the LSB Database Navigator shows 234 applications that are either ready or nearly ready for certification to the new spec.

You can download the LSB 4.0 beta specification, test suite, and developer tools at this link on the Linux Foundation site. ®