A runtime of our own

Serene now has a dedicated C runtime, and over the second half of 2025 it took shape. It gained persistent CHAMP/HAMT data structures and an event loop via libuv, and — replacing an earlier Boehm GC experiment — a custom, block-based memory manager (mm).

Along the way: tagged-union values, an atomic object-id counter, and gensym. See the runtime API reference for the details.