This is a maintenance and bugfix release. There should be no incompatibilities, and many small fixes. The one new feature is an optional speedup to system search. Users who have large directory trees to search, and stable sets of systems, can build a system search cache that will substantially speed up finding and loading system definitions.
Because this version does not cause compatibility issues, we strongly suggest that implementations move to replace 3.1.3 with 3.1.4.
Thanks to Faré for many bug fixes, to Dave Cooper for testing, and all who reported bugs and provided patches.
Best, R