Ask HN: Most interesting tech you built for just yourself?

I built a Markdown like text format for writing technical reports. I was fed up with Word and I wanted a plain text language that supports tables, footnotes, auto validated references to any part of the document, syntax highlighting of code blocks, comments, math equations, table of contents, etc... Unfortunately, existing solutions are all slow or written with some bizarre toolchains that are a pain to set up.

I wrote it from scratch in Go with very few dependencies, so I can compile it to a single binary that should work on all platforms. It outputs .html or .tex which is then compiled to a PDF via Xelatex. Since Latex is pain to deal with, I wanted to generate pdf directly, but life got in a way so... it's not exactly a finished project, but at least I enjoy using it.