Problem Areas Outside the Scope of Standards

In addition to those areas that can be (or are already) addressed in various standards, there are some areas in which the application vendor has the responsibility for ensuring that compatibility with the system interface has been maintained. In particular, dealing with version (and the accompanying feature) changes in system software is an ongoing task.

Some version differences that must be dealt with in Linux are

• kernel versions 2.2 and 2.4 - Between major releases of the kernel, several interfaces have changed and several subsystems have been (at least) partially rewritten. This requires both application software changes and updates to existing kernel drivers and patches.

• Linux distribution versions (for instance, Red Hat 6.2 and Red Hat 7.1) - There are different installation and system administration utilities, and different default system service and security settings, which must be learned.

• glibc versions 2.1 and 2.2 - Because backward compatibility has been maintained, there is not much change required in our product to deal with these two library versions (apart from upgrading ``known bad'' versions of the libraries).