I have in the past, and continue currently, used the handle "thanatos" on a lot of Internet sites, and if that isn't available (which happens ~50% of the time), "deathanatos".
"Thanatos" is the name of the Greek god or personification of death (not to be confused with Hades, the Greek god of the underworld). "Dea" is a natural play-on-words to make the handle work in situations where the preferred handle has already been taken, without having to resort to numbers and remaining pronounceable. I adopted the handle many years ago — at the time, I was reading Edith Hamilton's Mythology, and Piers Anthony's On a Pale Horse, both still favorites of mine, and the name was born out of that.
When I created the handle, I was fairly young, and valued privacy while online, not giving out my name. As I've become a more competent programmer, I'm starting to want to release some of my private works under FOSS licenses and such, and sometimes under my own name. This has started to tie this handle with my real name. I've become increasingly aware of my "web image" in the last few years, as I've been job hunting. As a programmer, I have a larger-than-average web presence, and I've started to wonder: Is this handle name professional? Does a handle name matter in a professional sense? Should I "rebrand"? (While one obviously wants to avoid hateful or otherwise distasteful names, is a topic such as "death" (to which my name is tied) proper? What could be frowned upon?)
To try to make this a bit more programmer specific: Programmers are online — a lot — and some of us (and some who are not us) tend to put emphasis on a "web presence". I would argue that a prudent programmer (or anyone in an occupation that interacts online a lot) would be aware of their web presence. While not strictly limited to just programmers, for better or worse, it is a part of our world.