To try out a program you don't really have to install it on your computer. There are other ways of using an application on your PC without having to even bother with installing it on your hard drive.
Once of the simplest methods for running programs without installing them is by using Zero Install. This lightweight, intuitive applications allows you to launch applications in a portable version. Therefore with Zero Install you can create a dizzying array of programs that can be launched without previous installation.
Once you have launched Zero Installed you are right away presented with a list of proposed applications. These can be launched without installation. Among the programs you can find applications for audio editing (Audacity), listening to the music (Clementine), creating 3D animations (Blender) and watching video clips (VLC).
Once you have clicked the Run icon next to the program you can see it launch via Zero Install. If the program is not available on your hard drive, Zero Install will automatically download it from the Internet and launch the application. All the files downloaded by the program can be easily removed from your computer's memory.
Of course you can add your own programs that you can downloaded from the Internet. They are all available in the My Applications tab - here you can access the catalog of your custom programs.