Haiku is a free and open-source operating system compatible with the now discontinued BeOS.Haiku applications are usually available as HPKGs; however, unpackaged applications can be installed by using Haiku PackageInstaller for legacy BeOS apps or manually unzipping the install files into one of the non-packaged installation folders. Haiku comes with a set of mostly small yet essential applications. Core applications are an essential part of Haiku, as they serve many different purposes.