MIssion LOader, keeping with Freespace's tradion of FRED
MILO would be a stripped-down version of Freespace for quick-loading; no tech room or multiplayer and the like. Just the briefing and maybe the command briefings for the mission would be functional, to allow quick testing of missions.
It could then be run by FRED to quickly test a mission; it could also be run separately, with something like "milo C:\Games\Freespace\Data\Missions\shivanpie.fs2", with an optional switch "-nobriefing" to go directly to the mission with the default ships.
Not sure how much work this would be, but it would be a big help to FREDers