Puppy Linux/Adding & removing software

PETGet
The official software package for Puppy Linux.

DotPup
The community software package for Puppy Linux.

Debian
Puppy can install Debian packages with some tweaking. As these packages are made for other linux distributions and not puppy specifically, some install and function directly and well, but others may not work due to dependencies (system files) that the package maker assumes will be on your system, are not, due to the 'cut down' nature of the Puppy system. These dependencies need to be installed separately.

Slackware
Puppy Linux 3 had Slackware package compatibility.