This font is one of several which originates from ASCII art.
How it Works: Chat users send my chatbot (Voluspa) messages to be displayed in-channel, and Voluspa renders their messages in one of several fonts. This one, Voluspa 3, is the default font for display. It uses the block characters ▀, ▄, and █ to render 6 lines of "pixels" within only 3 lines of text - a hybrid of ASCII and pixel art.
The use of only 3 lines helps keep the messages from obscuring too much of the chat, while also preventing the bot from being kicked for flooding.
This font began life as ASCII art, which was itself rendered in monospaced fonts such as Fixedsys, Lucida Console, and Unifont. Now the art is its own font and the font-ASCII art circle is complete! :D
(Voluspa's display fonts are case-insensitive, and always produce uppercase output, no matter what is fed into them.)
The 3x6 pixel font from the Virtual Gremlin, an old game of mine. This font and the 5x5 font were used for most in-game text, as they're the only ones that have lowercase.
A few letters are allowed to break the resolution constraint.