Some Notes

ClamAV thinks it decompress zip method 9 files
In May 2005 the ClamAV Development team detected a problem with zlib - which knows an undocumented inflate64 that maps to the zip compression method number 9 (implemented in files inftree9 and infback9). However the support for that method is not being compiled into by default, so you have to recompile zlib to get support for it - zziplib will not do that on its own, nor will it check the actual availability. So, zziplib users might be handicapped if the meet a zip compressed with that method 9, at best they will get an error code back to the application but that is mostly not intuitive enough to point to the actual problem related to the last breed of zip/zlib compression methods. Effectivly you are restricted to methods 0 and 8.
Ogre3D + Win64/AMD64 + zziplib = ZZIP_DIR_READ error
As of December 2005 the thread at points to a problem in the 64bit variant of zziplib with some zip archives. The actual source of the problem is unknown. The Ogre project uses an internal copy of the zziplib library being statically linked. The latest zziplib version has been tested on a number of 64bit system in the meantime - however those are 64bit Unix variants (LP64). While Win32 (LP32) works okay there might be some buglet left for Win64 (LLP64) that I can't track down (system N/A to me) in the near future.
PHP5 does not know --with-zip
As of January 2005 I was hinted that some of the PHP problems might see a new show. In the past there were numerous queries about installation of zziplib to be useful as the PHP-ZIP module but I could not answer them. (I don't use PHP for real work). The standard php4 docs were obviously insufficient with saying to just configure --with-zip... but now even that option is gone and there is no hint anywhere telling of the replacement.
sourcebase.sf using modified zziplib code
In May 2003 I did notice that the sourcebase.sf project - providing a generic virtual filesystem for applications - has been reusing the zziplib code. However the code has been modified in a number of places and it was (at first) placed under real GPL. That library was supposed to be put under the hood of the GNOME desktop but at the moment it does not seem to go nowhere further. 2009-08-23