There are trademarks available for this use case. See for instance redhat and centOS or firefox and iceweasel. The main difficulties are that you have to provi

There are trademarks available for this use case. See for instance redhat and centOS or firefox and iceweasel. The main difficulties are that you have to provide some value/convenience (e.g. see krita on steam) and that if you mess up your project people might actually leave. For instance if the new MS office is dramatically worse people will drag their feet but will eventually buy it anyway, but when people did not like the direction of openoffice they did not stand for it and made libreoffice.