The default executable file format in Lubuntu is a .deb file. Compare to .rpm in some other Linux distributions, .dmg in Mac OS, or .msi (or .exe) in Windows.
See InstallingSoftware on the Ubuntu Community Help Wiki.
The simplest way to download and install known software packages is apt-get.
Go to Menu --> System Tools --> LXTerminal
sudo apt-get install name-of-the-package[Enter] or [return]
- To update the list of software available,
sudo apt-get update[Enter] or [return]
- To get upgrade availability,
sudo apt-get upgrade[Enter] or [return]
- To remove software,
remove name-of-the-package[Enter] or [return]
AptURL allows software packages to be installed by a click of a button or special link on a webpage viewed with a web browser like Firefox.
The AptURL protocol is a mini-application for installing packages from the Ubuntu Repository.
When downloading a .deb file, you'll have the option to open (and install) with GDebi. If you've already downloaded a .deb file; just double-click it to automatically use GDebi. Alternatively, go to Menu --> System Tools --> GDebi Package Installer and browse to find an already downloaded software package (or, one in a removable medium) to install.
See Using GDebi to Install Packages on the Ubuntu Community Help Wiki.
Browse through almost 30,000 available packages with Synaptic Package Manager. Go to Menu --> System Tools --> Synaptic Package Manager. Read the descriptions and mark the check boxes of ones you want with a click of the mouse. When you're ready to install, click the "Apply" check mark. You can also remove and reinstall and / or fix broken packages.
See SynapticHowTo on the Ubuntu Community Help Wiki.
The Lubuntu Software Center will show you several hand-picked packages for Lubuntu. Go to Menu --> System Tools --> Lubuntu Software Center Browse through a small collection of featured applications, categories and single packages. Search, read descriptions and add the packages you like to the "Apps Basket." This acts as a shopping cart feature. When your done browsing; click the Apps Basket button, review your choices and install.