Umlaut, developed at Johns Hopkins, calls itself an “open source front-end for a link-resolver.”  There are examples of connecting this to the Ex Libris SFX Link Resolver via API.  Umlaut provides more flexibility on the link resolver interface, and more integration possibilities.

Github page:

Code 4 Lib Umlaut page:

View a webinar by the creator of Umlaut:




Coral ERM

Coral Electronic Resource Management System is a full functionality EResources Management System developed in 2010 by University of Notre Dame Libraries.

Coral’s entire code base is free to download, and is being actively developed (as of May 2017), and usage is growing in the US and Europe.