Just developed a plugin for JOSM, the OpenStreetMap editor to help work with authors/ users. Has some basic functionality at the moment, but will get more stuff, especially as more of osm work is quality control, and networking with nearby users.
It has three actions, at the moment, 1)Opens up the built-in author panel, if it isn’t already visible 2) Open browser showing the openstreetmap.org user profile page for the selected user. 3) From all the map data in josm, just select all the data that belongs to the selected user. Also on the list is to improve the way it searchs and selects by user (it is quite dumb in the way it does it at the moment), so if there was a load of fish and chip shops tagged with chippy=yes, then these would also be selected if you asked it to search for the user called “chippy”.