ALCH, the Algorithmic Language for Chemistry, is a domain-specific language that allows users to design self-assembing chemical systems. It takes as input a human-readable C-like syntax and outputs a list of chemical reactions and DNA tile specifications.
Schiefer and Winfree's Chemical Reaction Network-Controlled Tile Assembly Model (CRN-TAM) is a theoretical model for chemical systems that can perform calculations and construct nanoscale tile systems out of DNA. Broadly speaking, we can think of the CRN-TAM like bytecode or assembly: a low-level description that directly encodes behavior. An expert can read assembly with some effort, but if you want to understand or create it, it's usually much easier to use a higher-level language. ALCH provides exactly that advantage for the CRN-TAM.
The linked paper is joint work with all listed coauthors; part of my contribution was to code a compiler and simulator for ALCH.