  We introduce the third major version of Metatheory.jl, a Julia library for
general-purpose metaprogramming and symbolic computation. Metatheory.jl
provides a flexible and performant implementation of e-graphs and Equality
Saturation (EqSat) that addresses the two-language problem in high-level
compiler optimizations, symbolics and metaprogramming. We present results from
our ongoing optimization efforts, comparing the state-of-the-art egg Rust
library's performance against our system and show that performant EqSat
implementations are possible without sacrificing the comfort of a direct 1-1
integration with a dynamic, high-level and an interactive host programming
language.
