CoCoA 5 screenshots

Emacs is an editor, CoCoA is a Computer Algebra System: and they communicate!
The first step is to download the two programs:
go to the CoCoA-5 download page for your operating system, download CoCoA-5 and Emacs, and follow the instructions to set up the communication between them.
Edit CoCoA-5 files with Emacs
Open Emacs, and within Emacs open/create a file with a CoCoA-5 extension (such as file.cocoa5):
there is a new menu called CoCoA-5, and the file has coloured text.

Among the nice features for EDITING in Emacs there are:

The only thing you need to know is the PANIC BUTTON which is CTRL G ;-)
Execute CoCoA-5 files with Emacs
There are many ways of EXECUTING commands in CoCoA, the basic one is CTRL RETURN.

Note: depending on your keyboard / Emacs version / operating system, the key combination might change:

Place the cursor at any point on a LINE in your cocoa5 file, and press C-RETURN
(this also starts CoCoA, if it isn't running yet)

(click to enlarge)

the whole line is executed in CoCoA (in the upper half of the window)
and the cursor is moved to the next line (in the lower half) ready to be sent with the next C-RETURN.

Now select a REGION in your cocoa5 file, and press C-RETURN

(click to enlarge)

the selected region is executed in CoCoA.