Software ⇝ Open Source Synth Patch Editors and Librarians

jSynthLib

An open-source multiplatform editor and librarian that support a lot of different synthesizers. Runs on Windows, OSX, and Linux

sourceforge.net/projects/jsynthlib/

Ctrlr

An open-source multiplatform MIDI hardware editor with a large library of downloadable panels.

ctrlr.org