Different kinds of ES: there are many different ways of architecting an ES, and even more ways of implementing it.
Fundamental approaches to building an ES. NB: there's no accepted "right" way of doing this (yet); if something is included here, it's not necessarily recommended!
- RDBMS Inspired (the core idea behind the ES Alpha/Beta/…etc approaches)
- a.k.a. "ES Alpha": RDBMS With Code in Systems (the t-machine approach)
- a.k.a. "ES Beta": RDBMS Beta (upgraded version of RDMBS-with-code-in-Systems)
- Aggregate OOP with Message-passing
- How NOT to do an entity system; entities the oo way with logic included