[simonh]

>…the edit controls behaviour could be changed in which case it could cause existing programs to behave differently…

You just add a new mode to the control that enables the new behaviour. Existing programs using it would work fine.

[mark-r]

Adding new features to an existing Windows control, particularly one that has existed since the dawn of time, is a much bigger deal than adding to a simple utility. The last time that happened they added a whole new control, the Rich Edit.

[simonh]

Oh come on, framework libraries add new features to controls in a backwards compatible way all the time.