Before it
Million-token context was a closed-model feature.
The problem
Open models could not match frontier context length at usable cost.
What it introduced
A very large sparse MoE with a million-token context under MIT, built on the sparse attention from V3.2.
Why it matters
It brought frontier-scale long context into open weights, and kept downward pressure on frontier pricing.
What modern models inherit
Open weights competing on context length and price.
What came next
Later V4 checkpoints through 2026.