More conclusions

src/pages/adt-optimization/conclusions.md

@@ -9,7 +9,6 @@ This work is based on [Derivatives of Regular Expressions][regexp-deriv], which
 [parsing-deriv]: https://matt.might.net/papers/might2011derivatives.pdf
 
 
-Stack machines versus register machines.
 
 [From Interpreter to Compiler and Virtual Machine: A Functional Derivation][interpreter-to-compiler]
 
@@ -20,5 +19,11 @@ Stack machines versus register machines.
 
 [Towards Superinstructions for Java Interpreters][towards-super] is a nice example of applying superinstructions to a interpreted JVM. 
 
+If you're interested in the design considerations in a general purpose stack based instruction set, [Bringing the Web up to Speed with WebAssembly][wasm] is the paper for you. It covers the design of WebAssembly, and the rationale behind the choices.
+
+Stack machines are not the only virtual machine used for implementing interpreters. Register machines are the most common alternative. The Lua virtual machine, for example, is a register machine. [Virtual Machine Showdown: Stack Versus Registers][stacks-vs-registers] compares the two and concludes that register machines are faster. However they are more complex to implement.
+
 [stack-caching]: https://dl.acm.org/doi/pdf/10.1145/207110.207165
 [towards-super]: https://core.ac.uk/download/pdf/297029962.pdf 
+[wasm]: https://dl.acm.org/doi/pdf/10.1145/3062341.3062363
+[stacks-vs-registers]: https://dl.acm.org/doi/pdf/10.1145/1328195.1328197