Single application session

cd /usr/share/xsessions
sudo nano appname.desktop

.desktop contents:

[Desktop Entry]
Type=Application
Exec=executable-name
Name=Application Name
Comment=Launch just this application

Then restart. You’ll see it as an option in the lower right after selecting your user.

Where to install software

An excerpt from a stack exchange post:

The above list is already half the answer of you Oracle JDK question, at least it gives several clues. The checklist to “Where should I install software X?” goes by:

  • Is it a completely self-contained, single directory software, like Eclipse IDE and other downloaded java apps, and you want it to be available to all users? Then install in /opt

  • Same as above, but you don’t care about other users and I want to install for your user alone? Then install in ~/.local/opt

  • Its files split over multiple dirs, like bin and share, like traditional software compiled and installed with ./configure && make && sudo make install, and should be available to all users? Then install in /usr/local

  • Same as above, but for your user only? Then install in ~/.local

  • Software installed by the OS, or via package managers (like Software Center), and, most importantly, which any local modification might be overwritten when update manager upgrades it to a new version? It goes to /usr