Revita is a novel approach that uses AI to support learning foreign languages — toward advanced proficiency. Revita supports learners and teachers via deep personalization: tailoring practice sessions to the learner's current skill level — while continually monitoring the skill level. Learning material is created automatically from arbitrary authentic content, which learners can choose from anywhere on the Internet. Revita also facilitates learning "smaller" languages, which have limited materials and tools needed to support learning and teaching.