cartography - Which true type editor do you use to create/modify point symbols for GIS?

Which true type editor do you use to create/modify point symbols for GIS and what are the advantages and disadvantages of the tool?

I am looking for a true type editor to create/modify custom point symbols used in GIS. Here are some examples of symbols I want to create:

I am not familiar with the structure of a true type. But I guess that a true type contains many features which are not interesting for GIS (e.g. kerning). So the true type editor should be easy to use by a GIS analyst. I tried to get informations about true type editors by reading some descriptions in WWW (e.g. FontCreator). Before I test (or buy) a program I first want to get informations which editor is good for “GIS symbols”.

Both commercial and free solutions are welcome.

Answer

Here is another tutorial on using Inkscape and FontForge: