The phrase open source installer can have several meanings in computing. It can refer to an installation tool that is created and distributed on an open source basis. Alternatively, it can refer to a tool used for installing an open source operating system, such as those based on Linux.
The first definition of open source installer can cover both tools for installing a particular application and systems for creating installation tools. An example of the former is an installer designed to put the Java system onto a computer. This can be useful because there are many different variables involved in installing a Java system. Because the installer is created on an open source basis, it is easier to set it up so that people who download and use it get the precise combination of Java-related settings they should have on their machine.
An open source installer can also be a system of tools used to create installer files. These are the files that users download and run in order to physically install an application onto a computer running an operating system such as Windows. This can be a complex process, as the software must correctly interact with the operating system, other software applications, and the computer's hardware, without any conflicts. Using an open source installer is often an inexpensive and easy way for a software developer to take care of this process.
The second definition of open source installer covers the various techniques used to install an open source operating system. This can be a complex process for novice users, particularly those who want to run the new system alongside Windows. A simple-to-use installer can be vital in helping people skeptical about Linux-based systems to make the switch.
The most common form of this type of open source installer is a CD-ROM. This can either be distributed in physical form, such as being attached to a magazine, or through downloadable files that are burned to a disc by the user. In most cases, the CD-ROM will run automatically, with the user prompted to select settings in a similar way to installing software applications.
Many open source installers also come with the option of running the operating system without installing it onto a hard drive. These usually come in the form of a "Live CD" that can load the operating system into the computer's memory each time it boots up. This can be useful for people who want to try out the system, or need to run it on somebody else's machine and thus can't install it permanently. Some versions of open source system are small enough that they can run in the same way from a USB memory stick.