Installing Applications in Ubuntu

There are a number of ways to install applications on the Ubuntu desktop.  You can use the Ubuntu Software Center, apt-get from the command line or download applications from the Internet.  One aspect of install is understanding your operating system requirements.  This article will help you work through each of those options.

Historically, installing applications in Linux has been a difficult task. However, this has become dramatically easier in recent years as Ubuntu implemented a 'one-click' installation tool called Ubuntu Software Center.

Ubuntu Software Center

There are thousands of software applications available in the Ubuntu Software Center . Most applications are free and licensed under GPL, but some are priced according to their use or popularity.

The Ubuntu Software Center can be launched by clicking on its icon in the panel. When the main window opens, it displays new and featured software, a list of categories on the left, a search box in the upper right, and buttons to filter your search results in the upper left.

Each software application can be rated by users, and the average rating is displayed for each program out of a possible five stars.

Suppose we are looking for a program to help us design circuits. Typing circuits in the search box would show all software relating to that keyword. In this case, there are six applications that contain the keyword circuits in their title or description. The average rating and number of reviews is displayed for each item in the list.

Towards the bottom of the window is the command to Show 29 technical items. If clicked, Ubuntu Software Center will display lower level, system applications that are not useful to the majority of Ubuntu users.

After looking through the applications displayed in the list, we would like to install Scilab. Clicking on the application highlights Scilab and displays two buttons. We can choose to install the program or read more information, which includes a description of the software and user reviews.

It is possible to install the application when it is highlighted or after clicking More info. The additional information is very useful in determining if the application should be installed. Screenshots may be available and user reviews often indicate if the program still has bugs, lacks important features, or is all-around a great package.

After the program is installed, the Install button changes to Remove. With Ubuntu Software Center you can install and remove programs with a single click.

You will notice that an icon appears in the panel that allows you to launch the newly-installed program. Left-clicking the icon will launch the program and right-clicking the icon will allow you to choose whether or not the program remains in the panel.

As shown in the image above, the Scilab icon has been clicked on with the right mouse button. You can now choose to launch Scilab or unlock it from the launcher. Unlocking the application will cause the icon to disappear once the program is closed.

Note that unlocking an application from the launcher does not remove it from your system. You should uninstall programs using Ubuntu Software Center if possible. Using Ubuntu Software Center for the management of software will make it much easier to maintain your system.

Ubuntu Software Center uses a database of software that is composed of several sources, or repositories. There are several sources set up by default with every new Ubuntu 12.04 installation. You can view these sources by going to Edit, then Software Sources... in the top menu bar.

The Ubuntu Software tab allows you to choose which predefined software sources you would like to use. Much of the software available for Linux is open source. This means that the software is free to use and the source code is available to view and modify.

Some Linux users prefer to use a system comprised exclusively of open source software. However, certain tasks, such as configuring devices, are more difficult with this added constraint. Therefore, using some proprietary software to supplement open source programs is often desirable.

You may find that an application you would like to install is not part of the predefined sources shipped with Ubuntu. In this case, it may be possible to define a new source so that Ubuntu Software Center can locate the application and install it with one click.

Clicking on the Other Software tab allows you to define your own software source. Simply click on Add... and you can copy and paste the web address of the repository. The address of the repository is typically given on the official website of the program you are attempting to install.

At some point, you may be tempted to install a program outside of Ubuntu Software Center to avoid going through the steps of first adding a software source. However, the benefit of Ubuntu Software Center is that a single interface can remove, update, and manage all of the applications it has installed. Side-stepping this interface is sometimes necessary, but increases the burden on the user to manage software.

Installing Software with 'apt-get'

System administrators or advanced users may prefer the command line to install and manage software. The command line is a powerful tool that allows the automation of tasks, fast execution of complex operations, and the execution of custom functions, among other things. A command-line, text version of Ubuntu Software Center essentially exists in the form of apt-get.

If you are not comfortable with using a command-line to execute tasks, it is advisable to use Ubuntu Software Center to install applications. Installing software with apt-get typically involves a command similar to the following:

sudo apt-get install scilab

This command can be broken down into several, simpler elements. The first word, sudo, gives you temporary administrator (or super-user) privileges. Following sudo is the command apt-get. This is the actual command that will do work with super-user privileges.

Next is an option, install, that tells

apt-get you want to install a program. Lastly, scilab is the name of the package to be installed, assuming apt-get is able to find it.

In order for apt-get to install your desired application successfully, the name of the package must be entered correctly. Similar to Ubuntu Software Center, the desired package must be part of a software source that is configured. Software sources can be added to /etc/apt/sources.list for use with apt-get.

Installing software using the command-line is not as easy as Ubuntu Software Center, but it is useful or required for system administrators, for example, who are performing work on a remote workstation without access to its graphical user interface.

Downloading Software from the Internet

There are several websites that have vast collections of Linux software available for download. One such website, www.sourceforge.net, is very popular and has an easy-to-use interface. Since Ubuntu is based on the Debian Linux distribution, software packages compiled for Ubuntu typically have a .deb file extension.

Once the file has been downloaded, right-clicking the icon will produce the menu shown to the left. The first option in the menu is Open With Ubuntu Software Center. This option is possible with .deb packages because this file format is natively used by Ubuntu. Packages created for other Linux distributions may be very difficult or impossible to install. However, due to Ubuntu's popularity, there are usually .deb versions of open source software available for download.

If a pre-compiled package is not available for a particular application, the remaining alternative is to download the source code and compile it manually. This is essentially how all software was originally installed in Linux, and is only recommended for advanced users. One major reason to use Ubuntu Software Center is that it automatically resolves all dependencies to ensure your new application has everything it needs to run in a stable manner on your computer.

Useful Linux Software

A default installation of Ubuntu comes with many great, open-source applications. However, with thousands more out there, there are programs that are not installed by default that could save you time, money, or simply be a source of entertainment.

TeamViewer is a very easy-to-use application that allows you to share your desktop, view and access a remote desktop, and transfer files. To use it, you and a friend simply open TeamViewer. The client computer that will be connecting to a remote workstation needs the ID and password displayed on the remote computer. Once those two numbers are entered on the client computer, a connection is established.

TeamViewer makes it very easy to configure whether the connecting machine can control your computer or only view your actions on the desktop. It is great for remote trouble-shooting, training, or presentations.

In addition, the file transfer capabilities in TeamViewer simplify the task of sending files that are too large for email. This program is free for personal use, but requires a license fee if used in a commercial setting. It is a recommended application for anyone who sends email or periodically has computer questions.

Although Linux provides an environment free of viruses, disk fragmentation, and the blue screen of death, it is sometimes convenient to still have access to Microsoft Windows.

VMware Player lets you install an operating sysem 'inside' Linux and run it virtually. In addition, the operating system running within VMware is isolated from the rest of the files on the computer.

For example, a virtual instance of Windows 7 may become infected with a virus, but Windows is not aware that the Linux system (and your critical files) exist anywhere on the hard drive.

recordMyDesktop is a nice program that easily captures your desktop activity and encodes it into a video. It has the ability to record audio, as well, and can capture only portions of your desktop if you are focusing on a certain program.

This is a very useful tool for creating demonstrations or simply recording your actions to serve as a reminder later.

There is no better way to take advantage of your new- found immunity to viruses in Linux than installing ClamTk. This program will scan files for Windows viruses without any threat to your own operating system. If you have other Windows computers in your house, this is an invaluable tool that can safely check files before letting them loose in Windows.

Required Information About Your System

If you download software from the Internet to install on your system, you will need some basic information to ensure your new applications will work.

This information can be found by clicking on System Settings, which is located in the panel by default. Next, click on Details. The window shown on the left will appear and contains basic information on your system.

You should note the name and version of your Linux distribution, which is Ubuntu 12.04 in this case, and the OS type. Most computers are now 64-bit, but older computers may still use 32- bit technology.

It is necessary to choose software that is compatible with your Linux distribution, version, and operating system type. Once this information is known, the amount of free, open-source software you can obtain for your computer is only limited by your time.