Club Linux Coffs Harbour

A while ago we got this query via the contact form on the site, and as it's a question so often asked, I think it's worth putting the answer somewhere Google can see it.

I have loaded Ubuntu 8.04 and all is well except when I download other programs eg Banshee I have no idea how to install it or any other app. This is generally a very easy task in windows.

Those of you who have used GNU/Linux for a while are now doubtless spraying the screen with bikkie crumbs as you shout "It's EASIER than in Windows!!!", but there are good reasons why a new Ubuntu user wouldn't know that.

As user-friendly as the Add/Remove Applications utility is, out of the box it doesn't list all (or even much) of the software available in Ubuntu. Ubuntu's software repositories are categorised into four sections, Main, Restricted, Universe, and Multiverse. Of these, restricted and multiverse contain non-free software or software which may not be free software in some countries (like Australia) which recognise patents on software (thanks, Mr. Howard). Obviously if you use software from either of these repositories, it's at your own risk, since if it's non-free software neither Ubuntu nor anybody but the software's copyright holder can legally fix any faults with it.

The bulk of the software available in the official Ubuntu repositories is located in the universe section, and universe is not enabled by default (go to System -> Administration -> Software Sources to do so). Why not? Ubuntu is essentially a modified version of Debian GNU/Linux. The latest release of Debian contained over 23,000 software packages. A new version of Debian is released "when it's ready". Ubuntu, however, is committed to a new release every six months (give or take a bit). A new Ubuntu release consists of a "snapshot" of the "unstable" version of Debian currently under development, some modifications and customisations, and a lot of testing and bug fixing on a subset of the software in Debian.The six-month release cycle doesn't give enough time to rigorously test all 23,000 packages, so only a minority (generally the most popular) of these make it into the officially-supported main section.

However I never hesitate to enable the universe section. It's long been said that "Debian's unstable is more stable than other systems' stable", and it's rare to find a package that has serious problems.

Even with the universe section enabled, you may still not find the software you're after. The mum-and-dad-friendly Add/Remove utility focusses on general-purpose software with a graphical user interface, so if you're looking for something really specialised you may not find it there. Go to System -> Administration -> Synaptic Package Manager for the full, geekier list of what's available.

And that's it really. For 99.9% or so of the population it doesn't get any harder than finding what you want in a list, checking a checkbox, and clicking on the "Apply Changes" button.

If you still can't find the software you're after, it's probably either:

• so specialised or bleeding edge that it's probably not a good idea for a novice user to try it, or
• it's non-free software and it's not a good idea for anybody to use it. 

However, if you absolutely can't live without something that's not in main or universe, or you need to run the absolute latest version of something that can't wait for the next Ubuntu release, you still almost certainly don't have to download source code, compile it, and deal with "dependency hell". Often software not available in your operating system's official package repositories can be found in third-party repositories. Adding additional repositories is simple, but it can't be stressed enough that you need to trust the operator of the repository. This isn't Windows, you know; blithely installing software from just anywhere is not regarded as civilised behavioiur.

If the third party repository is operated by a developer of the software, or by the regular package maintainer of the software for your operating system (in the case of a bleeding-edge "backport"), you should be relatively safe (from either maliciousness or incompetence). There's a service provided by Canonical (principal sponsor of Ubuntu) called Personal Package Archives (PPA), which helps software developers maintain a package repository. You can often find what you're looking for there, but don't expect (much less demand) perfection from the software; the purpose of these repositories is often to help brave volunteers find bugs that are sure to be in very raw software.

If you can't find a properly maintained repository, some software can be downloaded and installed as a single package from the developer's website. Even if you find the right package for the current verion of your operating system, this should be avoided if possible, because on the next release of Ubuntu, your system will know where to find upgraded versions of every part of itself except this manually-installed package, possibly leaving you with a piece of software which no longer works because it's incompatible with the current version of your operating system.

You can sometimes successfully install and run packages not designed for the current version of your operating system. You might even be able to convert an RPM package (for Fedora and derivatives) into a DEB package (for Debian and derivatives) or vice versa and get it to work. Trying this is really not recommended. Your chances of success improve if the software is small and simple, but ask yourself: if this software is any good and been around long enough to be stable and reliable, why isn't it already in Ubuntu's official repositories, or at the very least in a repository run by a reasonably trustworthy third party?

Sometimes, though relatively rarely, you'll come across a program distributed as an ordinary compressed archive of files. Often this will simply be labelled as the version of the program "for Linux". Run a mile. Without the metadata contained in a package file your system won't even know how to get rid of the program when, as is quite likely, it fails to work. Usually the people who distribute software like this are proprietary software vendors who lack the expertise or inclination to produce a proper package for any of the free software operating systems, and who don't want to allow others to do that work for them.

Finally, never, never, never attempt to compile and install software from source code unless you are a software developer or are learning to become one. It used to be sometimes necessary for ordinary users to compile software way back in the mists of time, and you may stumble upon some very outdated documentation saying you should do it (particularly in the case of the Linux kernel), but it is definitely not necessary these days, and potentially very dangerous (particularly in the case of the Linux kernel).

So in summary:

• Many users will be perfectly happy with the selection of software in the "main" section of the official Ubuntu package repository.
• Power users will almost certainly want some software from the "universe" section.
• If you still can't find what you're after, and you don't mind taking the risk of possibly installing something unstable, third-party repositories can be useful.
• Do not manually download and install precompiled software if you can possibly avoid it.
• Don't even think about downloading, compiling, and installing something from source code unless you're a software developer.