90's System's Development Director here: I'd figured that enriched text/html like formatting would make its way into source code e.g. imbedding hyperlinks/tool

90's System's Development Director here: I'd figured that enriched text/html like formatting would make its way into source code e.g. imbedding hyperlinks/tooltips to relevant documentation/screen shots/test debug cases, critical section of code highlighted in red, section of code kept for legacy in grey, annotated code with comment bubbles - this sort of thing. The latest IDE's are certainly doing more of this with code highlighting and autocompletion, but IMHO it could still be easier for coders to more visually annotate and document code.