LibXp.so.6 missing 15.10
This might not be a perfect or ideal solution, but if you download the .deb for the previous ubuntu release (15.04), it seems to install just fine on 15.10. A program that depended on it started working immediately after I installed it.
http://packages.ubuntu.com/vivid/amd64/libxp6/download
Ubuntu Wily has no package named "libXp". Only solution I have found is to install the one from the previous version (download the deb file, install manually). I can't find any justification for this droppage, appears just a goof.
There's a bug report against Ubuntu Wily about it, but no response. https://bugs.launchpad.net/ubuntu/+source/libxp/+bug/1517884
libxp.so is REQUIRED for SAS, a commercial statistics program.
This worked for me:
sudo add-apt-repository ppa:zeehio/libxp
sudo apt-get update
sudo apt-get install libxp6
Caution: it requires adding a PPA, so think twice b4. To remove the PPA run
sudo add-apt-repository --remove ppa:zeehio/libxp
Source1, Source2