ImageJ

Thanks to a lot of help by Robert Futrell, Fiji's Script Editor learnt ImageJ's macro language. Now you can enjoy the power of full undo and of syntax highlighting when writing macros!

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For further convenience, the Macro Recorder opens newly created macros in the Script Editor, too.

Another nice consequence is that Ctrl+Shift+N (or on Macs, Apple+Shift+N) opens up the Script Editor.