Roberto:
a program to write simple staff notation tunes and save them, for instance as images (jpg. etc)

My choice of tools makes this easy once you've worked out the correct invocations:
abcm2ps to convert abc text notation to postscript
gs (ghostscript) to convert to any of about 100 formats for graphics and printers, in many resolutions.

We used this to make 300dpi PNG graphic file which we could import into a word processor doc to make Mary's song book.

I'm running them in Linux but there are WIndows versions avaible via the above links.

Also recommended for ABC users: Guido Gonzato's The ABC Plus Project homepage with really excellent documentation. I've printed and comb-bound the PDF documentation and it's my standard ABC reference book, a pleasure to use.

Anahata