2009.08.21 17:12 "Re: [Tiff] Libtiff 3.9.0 Released", by Jay Berkenbilt
Also of note is that due to libtiff 3.X.X not using proper shared library naming conventions, the name of the shared library produced from 3.9.0 is the same as 3.9.0beta. This is a problem for any system which is already using 3.9.0beta since any dependent libraries/applications will need to be recompiled.
Starting with libtiff 4.0.0, libtiff will be using proper ELF versioning and will not be basing its shared library numbering directly on the libtiff version number.
I noticed this with the first alpha and was very pleased. I'm also very pleased that the soname for 4.0.0 is 5, which means debian, cygwin, and others who are currently using 4 won't have to deviate anymore.
OS distributions are free to apply their own shared library versioning rules in the mean time.
Debian used 4.2.1 for 3.8.2 and is using 4.3.0 for 3.9.0, for what it's worth. I bumped up to 4.3 because of the new functions.
Jay Berkenbilt <email@example.com>