Aren't you just one person?
Mostly yes. Firefly Web Services is mainly Felicia Betancourt, formerly a staff scientist at Lawrence Berkeley Laboratory, now a programmer. Nevertheless, she often collaborates with designers, user experience gurus, project managers and other experts on larger-scale projects.
By the way, more of Felicia's work can be found on Twitter, GitHub and CodePen.
Is this website built on WordPress?
Nope. WordPress is an awesome platform, but for a simple site like this that rarely has new content, it would really be overkill. For example, when someone requests a page from a WordPress site, the server generally has to make numerous calls to the database before sending the page; that's just a waste of time for a static site.(Plus, to be honest, WordPress is just too easy! Felicia will be blogging about how she built this site soon; see below.)
The FWS website was built with a PHP-based static file generator called Pico. One of the great things about Pico is that it lets you write in Twig, a templating language not unlike HAML in Rails, or Jade in Node.js. Such templating languages provide coding shorcuts, encourage modular code design, and have other features that make it easier to write human-readable, maintainable code.
Although Pico **can** handle simple blogging, the FWS blog will be published on CodePen. At the pro level, Code Pen provides great tools for teaching and demonstrating how to code for the web, so it was an obvious choice.