Puppy Linux

Applications such as AbiWord, Gnumeric and MPlayer are included, along with a choice of lightweight web browsers and a utility for downloading other packages. The distribution was originally developed by Barry Kauler and other members of the community, until Kauler retired in 2013. The tool Woof can build a Puppy Linux distribution from the binary packages of other Linux distributions.

Barry Kauler started Puppy Linux in response to a trend of other distributions becoming stricter on system requirements over time. His own distribution, with an emphasis on speed and efficiency and being lightweight, started from "Boot disk HOWTO" and gradually included components file-by-file until Puppy Linux was completed.[6][clarification needed] Puppy Linux started as Vector Linux based until it became a fully independent distribution.

Puppy Linux is a complete operating system bundled with a collection of applications suited to general use tasks. It can be used as a rescue disk, a demonstration system that leaves the previous installation unaltered, as an accommodation for a system with a blank or missing hard drive, or for using modern software on legacy computers.

Puppy's compact size allows it to boot from any media that the computer can support. It can function as a live USB for flash devices or other USB mediums, a CD, an internal hard disk drive, an SD card, a Zip drive or LS-120/240 SuperDisk, through PXE, and through a floppy boot disk that chainloads the data from other storage media. It has also been ported to ARM and can run on a single board computer such as the Raspberry Pi.

Puppy Linux features built-in tools which can be used to create bootable USB drives, create new Puppy CDs, or remaster a new live CD with different packages. It also uses a sophisticated write-caching system with the purpose of extending the life of live USB flash drives.

Puppy Linux includes the ability to use a normal persistent updating environment on a write-once multisession CD/DVD that does not require a rewritable disc; this is a unique feature that sets it apart from other Linux distributions. While other distributions offer live CD versions of their operating systems, none offer a similar feature.

Puppy's bootloader does not mount hard drives or connect to the network automatically. This ensures that a bug or even unknowingly incompatible software won't corrupt the contents of such devices.

Puppy Linux offers a session save on shutdown. Since Puppy Linux fundamentally runs in RAM, any files and configurations made or changed in a session would disappear otherwise. This feature enables the user to either save the contents to a writable storage medium, or write the file system to the same CD containing Puppy, if "multisession" was used to create the booted CD and if the disc drive supports burning. This applies to CD-Rs as well as CD-RWs and DVDs.

It is also possible to save all files to an external hard drive, USB stick, or even a floppy disk instead of the root file system. Puppy can also be installed to a hard disk.

The default window manager in most Puppy releases is JWM.

Packages of the IceWM desktop, Fluxbox and Enlightenment are also available via Puppy's PetGet package (application) management system (see below). Some derivative distributions, called puplets, come with default window managers other than JWM.

When the operating system boots, everything in the Puppy package uncompresses into a RAM area, the "ramdisk". The PC needs to have at least 128 MB of RAM (with no more than 8 MB shared video) for all of Puppy to load into the ramdisk. However, it is possible for it to run on a PC with only about 48 MB of RAM because part of the system can be kept on the hard drive, or less effectively, left on the CD.

Puppy is fairly full-featured for a system that runs entirely in a ramdisk, when booted as Live system or from a 'frugal' installation. However, Puppy also supports the 'full' installation mode, which enables Puppy to run from a hard drive partition, without a ramdisk. Applications were chosen that met various constraints, size in particular. Because one of the aims of the distribution is to be extremely easy to set up, there are many wizards that guide the user through a wide variety of common tasks.

Puppy Linux's package manager, Puppy Package Manager, installs packages in PET (Puppy Enhanced Tarball) format by default but it also accepts packages from other distros (such as .deb, .rpm, .txz, and .tgz packages) or by using third-party tools to convert packages from other distros to PET packages. Puppy Package Manager can also trim the software bloat of a package to reduce the disk space used.

On earlier releases of Puppy Linux, Puppy Unleashed was used to create Puppy ISO images. It consists of more than 500 packages that are put together according to the user's needs. However, on later versions starting with Puppy Linux version 5.0, it was replaced by Woof. It is an advanced tool for creating Puppy installations. It requires an Internet connection and some knowledge of Linux to use. It is able to download the binary source packages from another Linux distribution and process them into Puppy Linux packages by just defining the name of that Linux distro.[50] It is equipped with a simpler version control named Bones on earlier releases but on later versions of woof, Fossil version control is used.

Puppy also comes with a remastering tool that takes a "snapshot" of the current system and lets the user create a live CD from it, and an additional remastering tool that is able to remove installed components.

Puppy Linux uses the T2 SDE build scripts to build the base binary packages.

Because of the relative ease with which the Woof tool and the remaster tool can be used to build variants of Puppy Linux, there are many variants available. Variants of Puppy Linux are known as puplets.

After Barry Kauler reduced his involvement with the Puppy Project, he designed two new distributions within the same Puppy Linux family, Quirky and Wary.

Quirky – An embedded, less-stable distro with all files contained in an initramfs built into the kernel. It has simple module loading management but fewer drivers are included. It is used for experimental purposes.

Racy – A variant of puppy optimized for newer PCs.

Wary – A Puppy variant targeted at users with old hardware. It uses an older Linux kernel, which has long-term support and the newest applications.

Easy – A puppy variant in which the init script is completely rewritten and which uses originally developed application containers aside the conventional package management.

DistroWatch reviewer Rober Storey concluded about Puppy 5.2.5 in April 2011: "A lot of people like Puppy — it's in the top 10 of the DistroWatch page-hit ranking. I enjoy Puppy too, and it's what I run exclusively on my netbook. Maybe the only thing wrong with Puppy is that users' expectations tend to exceed the developer's intentions."

In a detailed review of Puppy Linux in May 2011 Howard Fosdick of OS News addressed the root user issue, "In theory this could be a problem — but in practice it presents no downside. I've never heard of a single Puppy user suffering a problem due to this." Fosdick concluded "I like Puppy because it's the lightest Linux distro I've found that is still suitable for end users. Install it on an old P-III or P-IV computer and your family or friends will use it just as effectively for common tasks as any expensive new machine."

In December 2011 Jesse Smith, writing in DistroWatch, reviewed Puppy 5.3.0 Slacko Puppy. He praised its simplicity, flexibility and clear explanations, while noting the limitations of running as root. He concluded "I would also like to see an option added during the boot process which would give the user the choice of running in unprivileged mode as opposed to running as root. Always being the administrator has its advantages for convenience, but it means that the user is always one careless click away from deleting their files and one exploit away from a compromised operating system. As a live CD it's hard to beat Puppy Linux for both performance and functional software. It has minimal hardware requirements and is very flexible. It's a great distro as long as you don't push it too far out of its niche."

In December 2011 Howard Fosdick reviewed the versions of Puppy Linux then available. He concluded, "Puppy's diversity and flexibility make it a great community-driven system for computer enthusiasts, hobbyists, and tinkerers. They also make for a somewhat disorderly world. You might have to read a bit to figure out which Puppy release or Puplet is for you. Puppy's online documentation is extensive but can be confusing. It's not always clear which docs pertain to which releases. Most users rely on the active, friendly forum for support." He also noted "Those of us who enjoy computers sometimes forget that many view them with disdain. What's wrong with it now? Why do I have to buy a new one every four years? Why on earth do they change the interface in every release? Can't it just work? Puppy is a great solution for these folks. It's up-to-date, free, and easy to use. And now, it supports free applications from the Ubuntu, Slackware, or Puppy repositories. Now that's user-friendly."

An April 2020 review of Bionic 8.0 by Igor Ljubuncic in Dedoimedo concluded, "Puppy Linux delivered on its happy message, and even exceeded my expectations. Now, I've always been a fan, and rarely had anything bad to say, so a positive result was kind of warranted. What really amazed me was not that this is a lean and fast little distro - it's the fact it manages to keep its relevance despite the obvious lethargy in the Linux desktop space. You may say, well, why bother - but if you have older hardware or travel a lot, Puppy gives you your own, complete work session that will boot and run pretty much anywhere, with tons of goodies and excellent configuration tools."