As of 0.20, Geany's caret (AKA cursor) is drawn as a 1-pixel vertical bar in insert mode, and as a 2-pixel horizontal bar in overwrite mode, and there's an option to decide whether it blinks or not.
While this makes sense, I would prefer to be able to choose what kind of cursor (horizontal, vertical or block) shows in every mode and to decide how fast the cursor blinks. (Due to nostalgia, I prefer horizontal cursors for inserting, and block cursors for replacing, and I prefer a faster blinking cursor which is more easily visible and somehow encourages working faster.)
You can at least set it to thin vertical line or block caret using this configuration option[1], but it doesn't affect overwrite mode at all.
[1] http://git.geany.org/geany/tree/data/filetypes.common#n45
Having started using geany recently I've grown quite fond of it but I also miss the ability to use and underscore as the cursor. More options in this area would be welcome.
The cursor is drawn by the Scintilla editing component used by Geany. Geany exposes all the options it has available (see reply from Matthew above). Scintilla is a separate project, requests for features should be made to that project, www.scintilla.org.
Thanks for your reply, I've opened a feature request in the Scintilla tracker for this: https://sourceforge.net/p/scintilla/feature-requests/1037/