It allows software developers to publish programs directly from their own web-sites, while supporting features familiar from centralized distribution repositories such as shared libraries, automatic updates and digital signatures. It is intended to complement, rather than replace, the operating system’s package management. 0install packages never interfere with those provided by the distribution.
Zero Install does not define a new packaging format; unmodified tarballs or zip archives can be used. Instead, it defines an XML metadata format to describe these packages and the dependencies between them. A single metadata file can be used on multiple platforms (e.g. Windows, Ubuntu, Debian, Fedora, FreeBSD and Mac OS X).
Zero Install also has some interesting features not often found in traditional package managers. For example, while it will share libraries whenever possible, it can always install multiple versions of a package in parallel when there are conflicting requirements. Installation is always side-effect-free (each package is unpacked to its own directory and will not touch shared directories), making it ideal for use with sandboxing technologies and virtualization.
The XML file describing the program’s requirements can also be included in a source-code repository, allowing full dependency handling for unreleased developer versions. For example, a user can clone a Git repository and build and test the program, automatically downloading newer versions of libraries where necessary, without interfering with the versions of those libraries installed by their distribution, which continue to be used for other software.
Version 2.4 of the Windows version of Zero Install has been released. Changes in this version include:
- Support for extracting CAB archives and Windows Installer packages (.msi)
- 0store verify and 0store audit now offer to automatically remove damaged implementations
- New 0store purge command removes all implementations from the cache (useful when uninstalling, manual deleting is difficult due to ACLs)
- New 0install central command opens the main GUI (same as ZeroInstall.exe)
- Fixed extraction of TAR archives with long path names
- Misc other bugfixes
- Updated to version 2.6.2