This is the classic logo for Parabola.

The original vectors/source files have been lost. Parabola-libre.svg
is a re-creation by Luke Shumaker <lukeshu@sbcglobal.net>

Files: 
  Parabola-libre.png   The "canonical" form of the logo
  Parabola-libre.svg   A vector copy of Parabola-libre.png
  Parabola-libre.svgz  A compressed version of Parabola-libre.svg
  facicon.ico          A tiny version of the logo for use as a favicon
  parabolabw.png       A B&W version used in the banner of the website
  
All of these are Copyright the Parabola Project, and are licensed under
CC BY-SA 3.0 Unported.