GNUstep's StepSync 1.0 Released For File/Folder Synchronization
GNU's GNUstep as a reminder is the open-source implementation of Apple's Cocoa API as well as Objective-C frameworks and other interfaces found on macOS. GNUstep is still around though in recent years we haven't been hearing much out of the project... But this weekend StepSync 1.0 was announced.
StepSync 1.0 is a tool for keeping folders/files synchronized, including for backup purposes. StepSync also allows for comparison of source/destination and other common operations among file synchronization utilities. I haven't really found any competitive advantages to StepSync over the countless other utilities and command-line alternatives in this space, unless you are looking for something with a GUI in the GNU space or a big fan of GNUstep.
Details on StepSync can be found via gap.nongnu.org or via the info-gnu list.