More learners are available in the
mlr3learners repository on Github
(https://github.com/mlr3learners). There also is a wiki page listing
all currently available custom learners
(https://github.com/mlr-org/mlr3learners/wiki/Extra-Learners). A guide
on how to create custom learners is covered in the book:
https://mlr3book.mlr-org.com. Feel invited to contribute a missing
learner to the mlr3 ecosystem!