I don't think that [4] can really be accurately characterized as producing general-purpose journal management systems. The OSF is more for study management and

I don't think that [4] can really be accurately characterized as producing general-purpose journal management systems. The OSF is more for study management and sharing results, although I imagine that you're referring to OSF Preprints (https://osf.io/preprints https://osf.io/preprints) which serves a similar function for pre-peer review results sharing. For [3], the actual platforms produced by Coko and its affiliates are more readily discovered here: https://pubsweet.org/ https://pubsweet.org/ http://substance.io/ http://substance.io/ Hadn't heard of [2] before- looks neat. We have [1] currently deployed for a couple of websites where I currently work. We've found it to be a bit of a pain and are trying to phase it out to some degree. It's basically a layer on top of WordPress to the best of my understanding (I haven't dealt too much with it).