I noticed these a while back, when they turned up in a blog post with a huge set of other ship designs (
link ) - even more than are actually included in the "graphics" folder. But for anyone that wants an attempt at explanation, wild speculation BEGIN:
The phase ships are pretty clearly all designed around the main "glowy bits", so they're almost certainly specialised; but they still have weapon mounts and are named as "assault" and "strike" frigates, so they aren't purely utility ships in the same way that freighters, tankers and munitions ships are - they're meant for combat, but they're still doing something differently. Now, whilst phase stuff has been around for a while, in 0.5a we got the Phase Charge Launcher, which is "excellent at p-space ship hunting" and has a "p-space microcloak". With that in mind, I'm pretty sure these ships have cloaking devices or travel in some sort of "alternate dimension"-y thing called p-space.
As for the munitions ships, Alex has said before that these are supposed to provide ammo in combat - but, for reasons that aren't too hard to imagine, they aren't particularly easy to balance: as things stand, such ships take up deployment and fleet points, but ammo isn't a pressing concern very often at the moment (and certainly not worth the cost of slowing your fleet down with an extra ship). I imagine the repair drone does what it says on the tin - repairs ships; but this, too, seems hard to balance, and probably wasn't added in because it's not ready yet. The construction rig seems different, though, and even less combat-ready. Personally I imagine this being used to set up outposts: but I could be wrong, and it could just be a giant repair drone. Likewise the Ox, which has the mining/repair look, but lacks any further clues.
As for the weapons/missiles, most of these are either old sprites or unknowable. It's also worth noting that there are about 6 unused crew sprites, too.
