Technically you can use any editor with either Blitz or AMOS.
Both, by default, save out in a tokenised format... Which has its advantages... But both also import ASCII files just fine.
I seem a bit harsh on AMOS in this thread, so I want to add that I personally spent a lot of time with AMOS (read my blog), and owe it my entire basis of computer programming understanding.
Blitz on the other hand I only got hold of after I was already quite competent in ASM, and while I didn't spend much time using it, it is clearly the more powerful of the two languages.
