I used to be a developer. I still do some programming for personal purposes.

I have written several utilities for myself and have deemed some of them good enough to publish online:

• A DjVu to PDF converter called dpsprep (not initially my own, but I am the sole maintainer after my rewrite).
• My take at extended file attributes called viat (virtual attributes).
• My dmenu twist called searchtool-gtk.
• A TeX-to-unicode input method helper called unicodeit-gtk.

I have published some notes related to mathematics:

• My personal notebook contains mostly math and algorithmic code, but also has some tools for working with LaTeX and BibLaTeX. At some point big text documents start requiring customized tools.
• Some folks from Bulgaria find my state examination note repository se2018 useful.

I have also published a few repositories for demonstrative purposes:

• For my website (repository), I have implemented some things that are usually handled by libraries - observables, reactive rendering, type-based schemas, abstract rich text, etc. It was a useful learning experience and I believe the code is concise enough to be useful as a reference.
• I have shared some Jupyter notebooks in a repository called 244 (the name is a UNIX permission pun).
• After digitizing several books, my process evolved into what I describe in the digitization-demo repository.
• In a university course on mathematical modeling, I created a simulation for neural impulses called neuronsim.

Finally, the following are obsolete (for me) and thus unmaintained:

• A X11 focus toggling tool called wintoggle.
• A library called subscribed that I developed for my neuronsim simulation. Ironically, I rewrote both since their inception in 2015 and now they are independent.

I chose my GitHub handle, v--, after trying a few other short strings in late 2013. It has since then become invalid.

I don't care enough to change it, however I will describe how my username mostly prevents me from using GitHub Pages. To quote RFC 952:

The last character [of a host name] must not be a minus sign or period.

Thus, v--.github.io/<project-name> is technically invalid. Nevertheless, for some older (pre-2016) repositories, GitHub allows me to use Pages - see https://v--.github.io/subscribed/. The same possibly holds for the GitHub container registry (although I have no intention to try).