Archives in External are under their own licenses.  See
http://www.freetype.org/
http://www.libpng.org/pub/png/libpng.html
http://www.ruby-lang.org/
for details on each, respectively.

Source in Source is as follows:
al.c, alc.c, alut.c, rboal.c, rboal.h -- written by me.  See license.txt for license.
font.c, png.c, main.m -- written by me.  See license.txt for license.
glu.c, glut.c, ogl.c, rbogl.c, rbogl.h, math3d_native.c, math3d_native.h, rb_math3d.c -- written by Yoshiyuki Kusano, hacked to pieces by me.  See http://www2.giganet.net/~yoshi/ for details.

The application produced executes Resources/Ruby/main.rb, with the cwd set to Resources.  The Font, PNG, GL, GLU and GLUT functions are always available, nothing needs to be 'require'd.

Contact Keith Bauer (OneSadCookie@gmail.com) with suggestions, bug 
reports, &c.