= Playing with the libgd library =

libgd is a 2D surface drawing package, useful for drawing things like orbits.   You can do GIF animations with it.

[[ gd12 | Animation of a cheesy thinsat in a cheesy Kepler orbit ]]

[[ ap02 | Illustration of apogee skew ]]

[[ ap02-link | Illustration of apogee skew ]] with link to attachment on other page