Making maps for new versions?

[(Jonathan Roy)]

Will crossedit 0.7 allow me to make maps for 0.90.2, or whatever
the latest version is? :)

If so, what do I need to do that? The archtypes file.. and anything
else? 

If possbile, I'd like to mess around with making my own map,
at least just a few simple ones to get the hang of it. :)