Shared library versions and naming

If a new version of a shared library is compatible with an existing library, we can make a new minor version of the library.
If a new version of a shared library is incompatible with an existing library, we must make a new major version of the library.
Constraint: it must be possible to continue running programs requiring the older version of the library.
Solution: a naming convention is used for shared library real names and sonames.