Nowadays strickly "luxemburgist", I don't know except us. Nevertheless, some grops inspired in Council Communist and German-Netherland Communist Left, reclaims "critically" great part of her ideal (see Wiquipedia or Communist Left in "broadleft"). Even currents inspired mainly in Italian Communist Left, like CCI, reclaims her.
Besides, you have authors like Walden Bello (some companions know much more that me about them)that reclaims Luxemburguist.
Historically, you have in the 3o's "Cercle Communiste Democratique" in France (in particular Henry Lefebre), or "Socialisme ou Barbarie". Also in "Bataille Socialiste" you have other parties specially influenced by Rosa's thougt. Also you have all the groups in the line of Communist Council (Paul Mattickk is an outstanding autor). Also rewiew BILAN, progresively inspirated in Rosa ideas, removing leninist "dogmas" out.
Also, some "troskists" reclaims Rosa's Legacy, but only the part that is useful for them: they reject or "forbid" his wiew on "national liberation" and "anti-imperialist", and only accept her criticism of bolsheviks like a "friendly" corrective. (Well, they have right their to reclaim only a part; but we also reclaim the whole (not dogmatically of course)