FontForge is an outline font editor that lets you create your own postscript, 
truetype, opentype, cid-keyed, multi-master, cff, svg and bitmap (bdf, FON, 
NFNT) fonts, or edit existing ones. It also lets you convert one format to 
another. FontForge has support for many Macintosh font formats.

From the README-unix file inside the source: 
  If you want to edit CID-keyed fonts (for CJK fonts) you may want to pull
  down the cidmap package from http://fontforge.sf.net/cidmaps.tgz
We have included it with our tarball, but you might want to check for a 
newer version just in case.  If you have it in the directory with the 
SlackBuild script, it will automatically place the cidmaps inside the package.

You will also want to have an extracted copy of the freetype source code
available inside the extracted SlackBuild tarball directory - in other words:
	/somedir/fontforge/
		README
		fontforge.SlackBuild
		fontforge.info
		slack-desc
		freetype-2.3.5/
Fontforge seems to build (and function) just fine without doing this (this is
at least true for prior versions), but it does look for the freetype sources 
while compiling, so it's probably best to make them available just in case :)