YACPKTool: 'Yet Another CPK Tool', Non-GUI but reliable and may have success in repacking CPK files.
Mod Loader
BlueAmulet's Mod Loader: A mod loader for EDF4.1, EDF5, & EDF6 that supports a variety of functions.
Weapon/Object Tools
SGOTT: A series of tools related to the SGO format. Includes examples of custom and rebalanced weapons for EDF 4.1, 5, & 6 (4 byte data not included yet)
Big Racer's Weapon Builder: A W.I.P. UI-based weapon editor for EDF5. An updated and further maintained continuation of this tool can be found here.
Unnamed EDF Tool: A tool for extracting and recompiling RAB & MRAB files. Can also compile missions in a C-style format. The original version of this tool can be found here.
Blender MDB Plugin: A plugin for importing MDB models into and out of Blender.
W.I.P (Still incomplete but mostly done) Documentation
EDF Model Viewer: A W.I.P tool that can view Earth Defense Force models directly.
CAS / CANM Converter: For Animations, Extract CANM from the CAS file. And CANM can be injected back into the CAS.
Unnamed EDF Tool: A tool for compiling and, to a lesser extent, decompiling BVM scripts using a C-style syntax. Best used for making EDF5 or 4.1 BVMs from scratch. The original version of this tool can be found here.
Another EDF Tools: Series of EDF tools, can compile/decompile BVM scripts using assembly-style syntax, parse/build RMPA waypoint formats, or parse AWE voice name lists.
EDF Model Viewer: A W.I.P tool that can view Earth Defense Force 'MAC' files visually, while also visually displaying information about the 'RMPA' waypoints.
ACE: ACE (short for Audio Cue Editor) is a tool for editing and previewing CRIWARE ACB/AWB files. It was originally developed for DB Xenoverse 2 ACBs but support for both older and newer ACBs used in some other games has since been added. (Need to add support for EDF but can extract the files)
Eternity Audio Tool: A tool for replacing audio streams. Make sure it's the same audio channel for it to work. This can't do voice lines easily since they're sorted unusually.
Another EDF Tools: The awe_parser.py corrects the names for extracted voice files.
BroGamer4256's Subtitles: This adds a subtitle window on top of the game when in mission. Can be used to translate EDF5 to any language.
The EVERYTHING MODDING PACKAGE (Every single EDF modding tool is in this package)