This is just one of over seventy Media Asset Management (MAM) systems covered in the Media Asset Management Guide. Also see descriptions of the workflows.
"ResourceSpace is an open source Digital Asset Management system originally developed for Oxfam by UK company Montala Limited in 2006. Montala continue to manage the project. It has been released under a BSD-style license. It requires PHP, MySQL, and the GD Graphics Library, and works with most web server software such as Apache. A particular focus is on the improvement of collaboration between users when assembling resources together for a project." - Wikipedia
ResourceSpace has its roots in non-for-profit organizations and is well established. The support company Montala offers cloud-based solutions, or a local installation is an option. ResourceSpace is built on the popular open source combination of Linux, Apache, MySQL, and PHP (LAMP).