installer

An installer is a software utility that prepares an application for use on a computer. It typically copies program files, configures system resources, registers components, creates shortcuts, and updates configuration databases or registries. Installers may also install dependencies, set environment variables, and adjust permissions to ensure proper operation.

Installers come in formats and styles across platforms. On Windows, typical forms include executable installers (EXE) built with tools such as Inno Setup or InstallShield and Windows Installer packages (MSI). On macOS, installation is often delivered as a package (.pkg) or as a bundle. Linux software is commonly distributed as DEB or RPM packages, or as source code.

Typical installation begins with compatibility checks and license acceptance, followed by optional component selection, configuration, and progress reporting. Installers may perform post-install tasks such as registering services or creating shortcuts, and may include rollback, repair, or uninstall options. Silent or unattended installations also exist for automated deployment.

Security and integrity are central to installers. They are usually code-signed, verify cryptographic checksums, and request appropriate privileges. Good installers provide clean uninstall paths and minimize changes to the system, reducing the risk of leftover components or corrupted configurations.

In modern software ecosystems, installers interact with operating system packaging systems, application stores, and enterprise deployment tools to manage installation, updates, and removal, while supporting localization, accessibility, and rollback capabilities.