I got tired of it being a royal pain in the ass to get fancy text
(defined as anything other than the Eagle CAD built-in vector font) on
the silkscreen of my boards. I wrote a Python 3 program (requiring
cairocffi) to generate an Eagle CAD library file containing "devices"
and "packages" of rasterized text, for use on silkscreen (or any other
layer you choose).
https://github.com/brouhaha/eagletext
Requires Python 3, cairocffi
Only tested on Fedora 23 x86_64 with Python 3.4.3, cairocffi 0.6, cffi
1.4.2, cairo 1.14.2
It will probably work on other reasonably recent Linux distributions.
I haven't the slightest idea how to get it working on Windows or
MacOS, though if cairocffi is available it may work.
I also can't tell you, even on Linux, what arguments you can use with
the "--font" option, other than that it has to be something the cairo
library understands.