FontAnvil is a script language interpreter for manipulating fonts. FontAnvil is substantially compatible with the PfaEdit/FontForge native scripting language, but FontAnvil is intended for non-interactive use; for instance, invocation from the build systems of font packages like Tsukurimashou. To better serve font package build systems in general and Tsukurimashou in particular, FontAnvil has no GUI and, to a reasonable extent, avoids dependencies on external packages.
Read the FontAnvil user's manual (PDF).
Use of FontAnvil on Windows is not officially supported, and the Tsukurimashou Project does not provide official binary packages of FontAnvil for any platform. Only the source code is officially supported, and only under Linux and Mac. However, a user has graciously contributed some unofficial binary packages for Windows.