**What kind of problems is it mostly used for? Please describe.** Nonlinear stiff differential equations with splitting **Describe the algorithm you’d like** The methods described in https://doi.org/10.4208/jcm.2005-m2019-0238 (see also https://doi.org/10.1006/jcph.1996.0193 for related earlier methods) **Other implementations to know about** NA **References** See above