Schemer (later renamed Scheme) was invented to scheme against Actors reprising Conniver, which was invented to connive against Planner.

See the following for the current state of the art including the latest Actor approach to Eval, which is more modular and concurrent than the Eval in Lisp and Scheme:

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3418003

The above article explains exactly how Actors are much more powerful than lambdas with mutable environments.