Simplexions screenshot

Simplexions is an experimental algorithm for online sequence prediction. Probability distributions live on the categorical simplex, a population of “simplexions” learns and predicts as the data streams past, and a single wake-sleep mechanism decides which members learn from each token and which take part in each prediction. The population evolves as it goes: new members are born from pairs of parents, and the least useful ones die off.

The reference implementation is a byte-level engine in C with optional OpenMP and Rust bindings, plus an SDL3 and Dear ImGui visualizer. You can watch a population track a small Markov chain on the probability triangle, or feed it a text file, see each byte coloured by how surprised the model was, and have it write from a prompt.

It’s the first research project in my Lean Machine portfolio. There’s no business model, just a technical hypothesis: that the algorithm has useful reach on real text. It’s early days, and each open design question is being settled by experiment.