* An asterisk denotes applications that I have used previously.
Archivematica - a free and open-source digital preservation system that is designed to maintain standards-based, long-term access to collections of digital objects. There is a LOC blog post about this system.
ArchivesSpace - A new application born from merging features of Archivists' Toolkit (below) and Archon. It's still on version 1. Here's a description and a helpful PowerPoint about it. The iSchool at University of Texas made an ArchivesSpace tutorial regarding creating a digital object.
*Archivists' Toolkit (AT) - "the first open source archival data management system to provide broad, integrated support for the management of archives"; I've used this before and suggest that it could be a good way to manage our special collections and archives metadata in one place. AT allows for export to MARC, MODS, DC, EAD, and even RTF files for simple finding aids. Windows & Mac
ESRI Geoportal Server - "a free, open source product that enables discovery and use of geospatial resources including datasets, rasters, and Web services. It helps organizations manage and publish metadata for their geospatial resources to let users discover and connect to those resources. The Geoportal Server supports standards-based clearinghouse and metadata discovery applications." This service was mentioned in UMD's DigiStew blog.
* EXIF Tool - "a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files"
eXtensible Text Framework - "a powerful open source platform for providing access to digital content. Developed and maintained by the California Digital Library (CDL), XTF functions as the primary access technology for the CDL's digital collections and other digital projects worldwide." An example of this application's use is the Mark Twain Project Online.
* MarcEdit - an application for editing and transforming metadata records. It handles much more than just MARC. Windows only
* Omeka - an open source CMS application that allows institutions and individuals to display digital collections and digital exhibits with Dublin Core metadata and tags. The application provides a WYSIWYG interface for administrators and the standard search/browse options for users. There are a variety of useful plug-ins for Omeka, including a geolocation tool that works with Google Maps. While Omeka provides some basic themes, one can "hack" the code to create a more customized look for a digital collection and/or digital exhibit. Some examples of digital projects with Omeka are in their showcase. The application is, also, available as a paid, hosted service through Omeka.net.
SobekCM - an open-source digital content management system created by the University of Florida for their digital collections
Viewshare - "a free platform for generating and customizing views (interactive maps, timelines, facets, tag clouds) that allow users to experience your digital collections." This visualization platform is provided by Library of Congress. Here's a LOC's blog post about this tool and a D-lib Magazine article about its use with an art collection. Pros: The platform could provides interesting viewing options by geography, charts, and timelines. Cons: The prior version of this platform, Recollection, was slow and glitchy. LOC may or may not have dealt with these issues. Viewshare is, apparently, now compatible with Omeka. The Fairfax Postcards Collection was created with both Omeka and Viewshare.
* VLC Media Player - "a free and open source cross-platform multimedia player and framework that plays most multimedia files as well as DVDs, Audio CDs, VCDs, and various streaming protocols."