Sotto vs SuperMemo

Sotto is open-source, self-hosted language-learning software for structured CEFR courses and private practice. Its course covers grammar, reading, listening, speaking, and writing, with advancement tied to demonstrated mastery; separate practice is not gated by course progression. A vocabulary and grammar memory graph uses SM-2 spaced repetition to schedule reviews and help shape adaptive listening. Learners can build classes from articles, papers, YouTube links, or topics, with material leveled to a CEFR course and citations provided. Configurable AI and speech services include OpenAI, Anthropic, Ollama, faster-whisper, and Kokoro; Gemini Live supports spoken translation. The application, database, and files run on the operator’s own stack, and the maker documents an offline setup using the learner’s hardware. Access options include a browser-installable PWA, a desktop launcher for macOS, Windows, and Linux, a terminal client, and workbook PDFs for iPad annotation. Sotto is free to run under AGPL-3.0, but users pay configured AI and speech providers directly. Content sent to cloud providers is subject to those providers’ terms.

SuperMemo has no write-up on Specifiction yet; its figures are above.