I assume it's bio as in short for biography, which can be fitting in the context of a blogging platform. This was at least my first thought upon seeing the domain, and I didn't make any association with biology, biotech, etc. until I saw your comment.
stekern|6 years ago
new_here|6 years ago
> Also, why .bio? Sounds like biotech web site.
Because we couldn't afford the .com and .io wouldn't sell. So we had to get creative. The idea is that your able bio can be found at able.bio/username