I took a look and was a little intimidated by the process of making my own font and converting it, as I know almost nothing about fonts. (Also FontForge crashes on my computer.)
FontForge is definitely the way to go… but I am also a bit noobish in using it.
I cannot for example, get into bitmap mode from an empty font… I have to import another existing bitmapfont and work from there on -.- which is kind of annoying… but it works.
If you have it in bitmap mode… it is VERY easy to create a pixel perfect bitmap font
I am using a selfcompiled version of FontForge on MacOS X
the new fonts are also copyleft
(public domain) as the other too… I think that I will never do a copyrighted/limited/unfree font