I was recently asked for a way to visualise HELM notation

HELM (Hierarchical Editing Language for Macromolecules) enables the representation of a wide range of biomolecules such as proteins, nucleotides, antibody drug conjugates etc. whose size and complexity render existing small-molecule and sequence-based informatics methodologies impractical or unusable.

The RDKit provides limited support for HELM notation (currently peptide) and a simple Jupyter Notebook provides an easy interface as shown here