[v_lisivka]

mcedit (part of mc) in gnome-terminal currently the best non-modal editor, AFAIK, especially when you like to use mc to navigate file system.

[tonypace]

What an unfortunate name. All search results are for the Minecraft editor.

It's also fairly obtuse for non-experts. A champion non-modal editor would have a learning curve as shallow as nano but more depth that could reveal itself over time.

[hvis]

It predates Minecraft by about a decade, I think.