OX
MSX graphics editor
OX is a multi-purpose 8x8 pixel block editor for screen 5. Parallax has used it for Blade Lords, Akin and Core Dump. It can edit up to 40 screens at once, and we used that to edit the Akin maps and Blade Lords worlds. But its use is best seen when used with DD-graph (or AGE): just press F3, and then select "load GE5". OX will convert the image to a set of blocks with corresponding map.
OX doesn't have a manual, but a little bit of help is found under F1.