BF

BF is an Atlus format that contains BMD messages. Dialog in Persona 3 and Persona 4 is completely handled by BF scripts. Currently, it's possible to convert BF to an editable format and back, though many commands are still unknown. BF is not to be confused with PMX which handles the animation data of cutscenes.

BFTool
Featured article: Amicitia (program) While TGE's all-in-one editor doesn't currently feature BF editing, one of the EXE files contained in the download, bftool.exe, can convert BF files to TXT and back. Usage is easy, just drag the file you want to convert into the EXE and it'll generate the new one. You can get it here.