CCP4 libraries don't increase soversion as recommended in the cited sources, because it would be additional thing to do and there are many things with higher priority. IIUC the primary benefit is that a few versions of the same library can be packaged and installed at the same time. When it's needed we'll bump soversion. Note that not all projects use so-version as autotools docs recommend. For example in Qt so-version == version. There are many libraries with 0.0.0 in my /usr/lib, which is just a default value in libtool, and many projects don't increase so-version on every ABI change, because if part of the ABI is experimental and changes often the version would go up very quickly. But if you come across any practical problems (with ccp4 libs) we'll try to help. Marcin