  In the digital age, the amount of data produced is growing exponentially.
Governments and institutions can no longer rely on old methods for storing data
and passing on the knowledge to future generations. Digital data preservation
is a mandatory issue that needs proper strategies and tools. With this
awareness, efforts are being made to create and perfect software solutions
capable of responding to the challenge of properly preserving digital
information. This paper focuses on the state-of-the-art in open-source software
solutions for the digital preservation and curation field used to assimilate
and disseminate information to designated audiences. Eleven open source
projects for digital preservation are surveyed in areas such as supported
standards and protocols, strategies for preservation, methodologies for
reporting, dynamic of development, targeted operating systems, multilingual
support and open source license. Furthermore, five of these open source
projects, are further analysed, with focus on features deemed important for the
area. Along open source solutions, the paper also briefly surveys the standards
and protocols relevant for digital data preservation. The area of digital data
preservation repositories has several open source solutions, which can form the
base to overcome the challenges to reach mature and reliable digital data
preservation.
