The PMD editor is also the PMX editor. It's the same program.
Actually, there's a standalone version of PMXEditor. From what I can say, it supports PMX format fully (compatible with PMX format version 2.1), with many external features for specially editing PMX models. It only works on 64bit versions of Windows, unfortunately; the explanation given was only 64bit OSs can ensure the requirement for modifying PMX models. There's also a 32bit version, but the author said it's just a test a might not function properly like the 64bit version.
Thank you for the information - good reference 
Ok, I was looking for the wrong thing, thank you for this and other things I've asked for your help on.
But I've run into something weird, when I converted the Neru model like the tutorial says, I tested it with a motion I made from the sample files that come with MMD and the joints started bending in weird ways, is the same thing true for you or did I mess up somewhere?
Mine version is fine - you didn't mess up; it's a glitch that sometimes happens with this type of conversion, most likely caused by the version of PMD you're using.
There is a fix for this. There's a tutorial on fixing the IK bones for converted PMX models somewhere here on DA. If you can locate it, it'll tell you to go around fixing this. My usual link reference is down at the moment so I can't give you the link, so unfortunately you will have to find it yourself.
There is a fix for this. There's a tutorial on fixing the IK bones for converted PMX models somewhere here on DA. If you can locate it, it'll tell you to go around fixing this. My usual link reference is down at the moment so I can't give you the link, so unfortunately you will have to find it yourself.
Thank you for your help again, maybe for your next tutorial you can explain about sph files, what they do, and how to make them. Because I've seen them in the files for models and accessories and I'm sure I'm not the only one that wonders about them.
Yeah, I was thinking about making a tutorial on sphere maps especially since the ones available are ... hmmmm, how should I say this ... "not accurate".