[swhipple]

The EPL is roughly in the middle of MPL and LGPL in terms of copyleft scope. MPL requires per-'file' source sharing. EPL requires per-'module' source sharing. LGPL requires per-'module' source sharing and separating the module to permit the user to use/replace it without additional restrictions.

The one downside that EPL has is that, unlike MPL (without "Incompatible With Secondary Licenses" notice) or LGPL, it is incompatible with the GPL-family of licenses. It specifies different conditions for providing the source code and has a governing law clause (New York).

It is popular in the Java ecosystem (Eclipse, Clojure, etc).