Version 3.73 offers a nifty new feature for scripters - word completion. To use this, start typing an inbuilt function name (eg. 'no' for Note) and then press Ctrl+Space in the notepad window. You will see a small list of all the script functions that start with 'no', and all you have to do is choose one and press <enter>.

I hope the hot key for this feature is changeable. ctrl+space is very easy to conflict with other programs, such as input language switch...
I'm not sure you can change it in the notepad. I note that MS Visual Studio uses the same hotkey for a similar purpose.
Do you have a suggestion for a better one?
Nice.. Now if this also had Scite like language coloring, especially with proper coloring for client functions, it would be perfect. Scite itself requires a recompile to just get it to color the commands different and you can't tell it to do something useful, like making them green, while language specific ones are blue, etc. All you can do is hand edit the basic language file to add every new command into the, "color this as well", list. Its a bit annoying. A decent coloring system would recognize those that are client specific and color them uniquely, reguardless of the language.
Still, command completion is a major step forward. I like!
ctrl+space is fine, just hope it can be set to other hotkey by user. You know it's useful feature and will be use quite a lot, if the hotkey is conflit with other system which is very possible, sometime user will wish they can set the hotkey to other.
There is no provision in MUSHclient to reconfigure hotkeys in the inbuilt notepad. Hopefully you don't need to switch input languages frequently whilst scripting.