Inkscape is great open source software (although it crashes frequently) which can import a bunch of formats including bitmap and DXF.
It can export into HPGL format, and the simple code below can be used to convert to Eagle script files.
I tried this with a DXF file from Solidworks and it worked well. Also it was possible to convert a bitmap image (Truetype
text) into line art using inkscape's 'trace bitmap' function, convert to HPGL and then convert to Eagle script format.
The code can be compiled using "g++ hpgl2eagle.c". To execute, type:
hpgl2eagle myinputfile.hpgl myoutputfile.scr
Source code is here because I have trouble uploading files to element14. If someone wants to enhance it or to generate an
executable and upload it somewhere that would be great (I tested on a MAC).
Hopefully one day someone can write an Inkscape plug-in that can import/export Eagle script files.