Is there any tool or IDE for the Haxe programming language that can automatically highlight errors that are detected in Haxe source code, like the Eclipse IDE's automatic Java error highlighting?
Take a pick from here: http://haxe.org/com/ide
As EzeQL said, FlashDevelop is the best option. However it doesn't run outside Windows.
Not on the list, but also worth pointing out is the MonoDevelop plugin.