[cogburnd02]

Another example for you: libcaca. [1] However, the GNU people recommend the X11 license for small programs and Apache 2.0 if you've already decided to use a permissive license on a large program [2]

[1] http://caca.zoy.org/wiki/libcaca [2] https://www.gnu.org/licenses/license-list.html#WTFPL