Most of my music writing is done on Sibelius, as I've no doubt mentioned before. While I still compose initially at the piano (normally -there are occasions when I write straight onto the computer), increasingly what's written down there on the manuscript is sketchy and gets transferred to the computer fairly quickly (before I forget what the scribblings mean). In fact, the extra manuscript books I bought to use for writing the musical (Grimhilda!) haven't been used. (Saving them for the next musical!)
Sibelius is a fantastic programme for composers and other musicians - I'm just finishing up transcribing a bundle of some 15 songs for a composer in Alexandra. And I think there are more to come. Her music has all been written by hand in pen or pencil up till now.
All this is a lead up to the photograph below, which I assume shows the very first version of Sibelius (we're now on version 7). I got this off someone who's signs him/herself as jwkay.
The manual that came with my version (that was number 4, and I use number 6 now) is thick and probably the best computer programme manual I've ever used. Excellent!