Before we go into the topic (PPA) of the post, I would like to enumerate the different sources for applications for a Ubuntu system organized into four separate areas or “components”, based on the level of support offered by Ubuntu and whether or not the program in question complies with Ubuntu’s Free Software Philosophy.
The repository components are:
Main – Officially supported software.
Restricted – Supported software that is not available under a completely free license.
Universe – Community maintained software, i.e. not officially supported software.
Multiverse – Software that is not free.
To put simply, A Personal Package Archive (PPA) is an online repository used to host the latest versions of software and application packages. PPAs offer the opportunity to install softwares that are not available in main or official app repositories. After installing an application from a PPA, you would be notify any time there is an update to the software package are available.
Every PPA contains the description of the app/software, how it can be added to your system or removed if possible.
It is a simpler way to make software programs available. If you’ve written a program, its source code can be built into binary packages that can easily be installed by any user without any necessary high technical knowledge.
Launchpad and PPA
Launchpad is a software PPA infrastructure that is created to make sharing, communication and collaboration in software development easy. Though it was created and supported by Canonical (the company responsible for Ubuntu Linux) it has been used to support other software projects outside the Ubuntu community. For anybody interested in software development – especially in Ubuntu – it would be a good idea to register and get familiar with launchpad. Then you can start to create your source package, upload it and Launchpad will build binaries and then host them in your own apt repository. Every individual or teams in laucnhpad can have one or more PPAs, each with its own URL.
The packages you publish in your PPA will remain there until you remove them, they’re superseded by another package that you upload or the version of Ubuntu against which they’re built becomes obsolete.
Activating a PPA
Before you can start using a PPA, whether it’s your own or it belongs to a team, you need to activate it on your profile page or the team’s overview page. If you already have one or more PPAs, this is also where you’ll be able to create additional archives.
Your PPA’s key
Launchpad generates a unique key for each PPA and uses it to sign any packages built in that PPA. This means that people downloading/installing packages from your PPA can verify their source. After you’ve activated your PPA, uploading its first package causes Launchpad to start generating your key, which can take up to a couple of hours to complete. Your key, and instructions for adding it to Ubuntu, are shown on the PPA’s overview page.
Deleting a PPA
When you no longer need your PPA, you can delete it. This deletes all of the PPA’s packages, and removes the repository from ppa.launchpad.net. You’ll have to wait up to an hour before you can recreate a PPA with the same name.
READ: How To install applications from PPAs.