Back in 2007 or so, I wanted to make a 100% free font that looked good both on the screen and when printed out. I decided to take Charis SIL, which is itself derived from a version of Bitstream Charter given to the X consortium under very generous licensing terms back in 1992, removed glyphs I wouldn't use (this font only supports Western European languages with some limited IPA support), made the spacing more reasonable (Charis has this really wide vertical spacing), and did some work on bitmap renderings of the font that I finally gave up on, realizing it would never be as readable on the screen as Verdana.
Bitstream Charter, Chortle's ancestor, is a font made my Matthew Carter, who later on became famous for his legendary Verdana, Tahoma, and Georgia fonts that are part of Microsoft Windows. Like Verdana (my favorite screen font; indeed the only proportional font I can stand looking at on the screen), this is a very beautiful and readable font. Unlike Verdana, the font doesn't have good hinting for the screen.
Chortle is a very nice font for writing text to be printed out; it has had problems with looking decent on the screen, which I have resolved by removing all hinting from the glyphs today (Fontforge's auto-hinting is so bad it's best completely removed). It's now readable in Windows XP and looks nice in Windows Vista (clear type really makes fonts look a lot better on the screen)
This will be my final release of Chortle; I did most of my work on Chortle back in 2007, and haven't touched this font for over a year. It's a nice font, and it completely free (both as in free beer and as in free speech).
It can be downloaded at samiam.org/Chortle