On Unix there is nothing to stop you from creating libfoo.so without a version number in the filename. Conventions for doing the latter part came about over time. As they did on Windows too (see msvcrtxxx.dll, where xxx is a version number). These days there is also WinSXS on Windows which I don't really expect HN users to know about and is probably not relevant to the historical context.
Microsoft did really fuck it up historically (IE overwriting shell32 comes to mind) but the mechanism didn't have problems when applied by the right hands (sometimes a first party is the wrong hands :P)
If you want to talk problems in the mechansim, ask me sometime how it's possible for a Win32 process to host multiple incompatible malloc implementations in the same address space.
"As they did on Windows too (see msvcrtxxx.dll, where xxx is a version number)."
I didn't use Windows enough to know more about it than that let you have multiple copies of the libraries. Did it let you upgrade a compatible library?
"If you want to talk problems in the mechansim, ask me sometime how it's possible for a Win32 process to host multiple incompatible malloc implementations in the same address space."
